2003 tundra air flow disaster

For the last half a year I've been dealing with what my mechanic claims to be a lack of air flow. We've changed the maf, sensors and, wiring. Starting the feel like the whole air flow system. We fix something works for a day the the problem starts back up. At first it was just stalling and cutring when the rpm was low at turns and stops. More recently on the highways its just started to almost bounce as if it's pushing through a stall because the engine is running. Any ideas what may be up? I also keep filling up my transmission with fluid because I have leak if that could be related. Feeling like killing my truck please stop from making a bad mistake lol

 

Check the coolant in the radiator, and the transmission fluid. May have to actually drain some out to see. It's easy to refill both to the proper level with correct fluid. Post up pics if what you find.

 

First thing I'd do is go to the local auto parts store and have them scan for codes, or buy a code reader. If the engine is chunking like that, chances are it's throwing a code.

My money is on fuel pump, but any number of things will make it go into limp mode. Unfortunately, told us jack about what year and engine you've got, much less how many miles.

Get codes scanned. Come back, tell us what codes popped (all of them), and give us more details about the truck.

 

Oem parts are important to use on these best gen trucks. Sometimes aftermarket junk can cause a lot of other issues that you end up chasing your tail over

 

More info on your truck would help. Year, engine config etc.
“keep filling the trans with fluid” is worrisome. Where is the leak? Is the plan to fix it?
Why does the mechanic think you have an airflow problem?
Throwing parts at an unidentified problem is always a bad idea and a waste of money. I would start with a new mechanic.

 

Air flow is usually the least likely of problems. Its the simplest part of what keeps your engine running. I'd look deeply into fuel and spark before I even suspected air.

 

Ya - unless some rodent has blocked your air filter housing or snorkel with a nest, it's unlikely an air problem. I'm sure your mechanic has already checked these.

 

My first thought after reading the OP's first sentence was get a new mechanic. The highway lunge you describe could be the transmission, and as knabores said is worrisome. I would suggest a competent indy mechanic to fix your leak before you ruin the transmission. The other issue is likely nothing big, and after the tranny fix can be addressed.

 

Your truck has a drive by wire throttle body.. First issue sounds like the maf is either bad or isn't calibrating with the ecu. I learned from playing with different intake tubes that moving the maf, or needlessly disconnecting the battery, can cause the ecu to restart the "learning" process to control the throttle body. The symptoms I got from that were strange idle and when coming to a stop the motor would stumble or shut off. The way through it is to drive the truck, it will adapt and it will operate the throttle body. What brand of maf was installed? If it doesn't say Denso or Hitatchi I would replace it and see if the problem leaves after about 20 miles of driving.

The other issue sounds more like a transmission problem. Use your dip stick, make sure you have the right amount of fluid. If you are low at all it will do strange things.

 

I've addressed and fixed the transmission fluid problem but the problem still persists. The truck is a 2003 Toyota tundra v8. Originally we thought it was an maf problem and replaced that then we tried replacing a sensor then the wiring. I'm not sure what is up what to do or where to go

 

Are there engine codes to address? What are the symptoms now?

 

GO TO THE AUTO PARTS STORE TO HAVE THEM PULL CODES.

It's been stated more than once in this thread. Pulling any stored diagnostic codes could provide a super-solid lead for directions to further troubleshoot, and it's 1,000% critical here. Most big-box auto parts stores like Auto Zone will pull codes for free. You can easily call ahead to ask if they have a code reader. They offer you this service because they'll usually give you possible suspects with it, in order to get you to buy parts.

 

I understand your frustration chasing these strange problems. My suggestion would be to download the techstream.

I ran it on my truck after the first transmission fluid change as one of the sensors is transmission temp. It has a live stream and capture function. If I had to guess - @Darkness is probably right and if you monitor the throttle position sensor and MAP, you'll probably see either a loss of signal or some other strange readings that will point you in the right direction.

This is the only thing I can think of that wouldn't set codes or have an obvious mechanical failure.

Hope you can track it down quickly.

 

And to this point - if you haven't had your codes cleared recently (like, nobody removed negative batt cable recently) and the auto parts store finds nothing, that is also a big symptom, one which limits the number of possibilities. Richid's reply points out one.

 

Dude, find a new mechanic. Someone throwing parts at it without a clue is not a good mechanic! Please pull the codes as many other s have said and post back.

 

There might not be any stored codes. But ya, his mechanic should have said that it needed a drivability diagnosis - I'm guessing he doesn't have a scanner to do it so he's just swapping parts.

 

Erased. Someone came up from behind and says he knows it all and others don't. So, don't buy one cause he said it's not needed. You can leave the house to have someone else do it for free, then you can go back home in a vehicle that at least started to get you there and back an hour or more later. All that when you could have been fixing it already after getting a code read or drinking a beer watching someone else fix it cause you know you can't. Good Luck OP.

By the way, you can clear the code and either it will immediately pop up again or eventually throw the code later. The O2 sensors are good for that. Bought my trk with those codes flying, kept clearing the codes till I could get around to it and slowly they stopped. Two years later still nothing but will change them out when doing the maint gig on the timing belt.

@ Richard. What I stated is a necessity for easy troubleshooting with no running around Timbuktu trying to get a free read cause your too cheap. If the vehicle doesn't start or barely runs you ain't driving anywhere for a freebie ck, but calling the tow trk with your thumb up the
if you don't know the problem. People worth their salt that know how to turn a wrench have one, and they know all about what you say too! Geeze.

A Pizza cost more than a basic scanner so no big deal for anyone to get one! Especially when owning older vehicles. Also, knowing the code saves people from dishonest mechanics saying it's something expensive when it's not. That's if they rely on mechanics for all repairs because they can afford it or not a wrench turner. Chicks who wear perfume and not coveralls and oil, per se, need the OBDII!

 

This will only work if a code is stored - and I'm sure any mechanic would have checked or you could go to an auto parts store today and get the codes for free.

Not every problem sets a code - only if it outside the predefined parameters. This is why you need more than a code scanner, which most mechanics will have. They may not have a Toyota module though.

Buy the cable instead and download techstream - this will get you the same software the dealer would use. If you don't know how, or aren't comfortable doing this, go to a dealer and pay for the drivability diag.

I'm not sure some people here understand that vehicles don't constantly 'have codes' - for example, there is no code for low oil level or a dead starter.

 

I haven't seen anyone imply or blatantly state that here, but maybe I'm wrong. Only that, when a car is running rough, or if it the money-light is one, if it has an OBDII port on it, the first logical thing to do is not even to go to a mechanic, it's to check for codes. If nothing else, it's going to give you at least some diagnostic direction, some idea of what's wrong.

Personally, I don't take my vehicle to my trusted mechanic unless I know exactly what's wrong. Any time I wasn't 100% certain what was wrong, I'd carry it to the stealership to let one of their techs diagnose it. I've never had to pay for more than 2-3 hours of labor the couple of times I've done it, but for damn sure I haven't had to throw multiple parts at it or take multiple trips for more diags. If I ever had a mechanic who failed to fix the core problem in two visits and still had no idea, **OR** didn't tell me at the first visit, "it could be X or Y, which do you want to go with", I'd think that mechanic didn't know WTF he's doing and promptly find another mechanic.

 

A coworker of mine had a code reader and gave me that these codes were there. P0031 p0051 p0057 p0101 p0102 p0330 afr 02. He then was able to tell me that all the cylinders were misfiring. He explained that the computer will retard things so that it won't hurt the engine and suggested starting with the throttle body and clean that up, then spark plugs then the coil packs.

 

ALL cylinders misfiring is not either of these things: Spark plugs, coils.
One cylinder misfire, sure, maybe a bad plug or bad coil, but not ALL cylinders.

I don't think this is an electrical issue if your buddy is right and misfire is happening on all of them. Remember: Most combustion engines only need three things to run: Fuel, air, spark. If spark isn't your issue, that leaves fuel and air.

It's correct, ECU will try to adjust to compensate for whatever its sensors are saying is happening. In my mind, I would think it either doesn't have enough fuel pressure to push correct fuel into all cylinders, or it can't get a legit air reading (from MAF) to calculate ratio.

Start with the cheaper. Clean MAF as suggested. If it doesn't help, and your truck hasn't had the MAF replaced in the last 100k miles, get a replacement Hitachi or OEM/Denso unit, they're cheap enough. DO NOT BUY ON scAMAZON!

If clean/new MAF doesn't fix the problem, I'm doubtful it's the fuel pump, and it's a little more of a pain in the ass to replace. But come back and tell us an update, maybe you'll find other advice here.

 

This is true, especially if by "throw a code" you mean the check engine light. Lots of problems won't light that. Some cars have vehicle specific coding that won't show up on cheap readers. A good reader, or a cable and software, will tell you more about the problem but you may need to understand how to interpret the data to know there is a problem.

I daily a VW GTI, I have had to use vagcom a few times to correct things that would not trigger a CEL and couldn't be solved by any other means. Calibrating the throttle body for example, or engaging the test for the cats to pass smog. Neither threw a CEL or a code, but scanning through the individual tests revealed that they needed attention. I also have a bad airbag circuit that I wouldn't know about, and an electrical short in the main control for my locks/windows. It's amazing what software and a cable can tell you.

 

Well dudes. I cleaned out the throttle body and it was riding great and clean for a little while. Worked up to feeling comfortable riding the interstate to run an errand and it cut out on me again when I was pulling into my neighborhood. Feeling really stuck. I appreciate all of you have commented. Thinking this problem is some underlying cause. Should I just get my engine serviced at this point or tell em about my problem? Definitely going to a new mechanic, just don't know how to approach the problem. Is there anything else I can do? Guy at work told me to check the spark plugs.

 

I ordered a mini-vci ODB2 cable off of Amazon and used techstream. If you use laptop with even a half decent battery, you should be able to get some good run times on the road to capture all the sensors. This is most likely to identify the cause.

Or find a mechanic with the Toyota/Lexus module on their scan tool - worst case a dealer can do a drivability diagnosis for you.

It may seem more expensive, but how much are you going to spend throwing parts at it?

Best of luck - intermittent issues are the worst.

 

If it was misfiring there'd be codes for that as well. You've got 2 maf codes, 3 o2 codes, and a knock sensor code.

 

Do you work at an automotive service center? If not, I wouldn't trust guy telling you "check the spark plugs".

Again, the chances of EVERY spark plug fucking up is nil, which is what it would likely take to see what you are. Just like every fuel injector won't be bad. Just like every coil pack feeding each spark plug won't be bad, they're individually wired, and individually coiled. That's why spark plugs make zero sense here UNLESS you recently had someone replace the plugs, and they replaced with the wrong units, because some of our trucks mandate you must use a specific plug, and it's done for a very specific reason.

(Your mechanic didn't replace your spark plugs recently, did he? If so ... you may want to look into that...)

Do yourself a favor. If you can't monitor what's going on, then replace your freaking MAF with a Hitachi or Denso unit just so we can take the airflow monitoring component out of the equation. You can easily do this on your own. Maybe you got a bad MAF, or your mechanic used shit parts? Maybe stop listening to coworkers, if dude was the king of automotive diagnostics, he probably wouldn't be working his current gig.

If your MAF is not taking correct measurements of air flowing into the engine, the ECU will be totally unable to understand how to adjust fuel/spark ratio and you'll see all kinds of fucked up shit happening. It's a cheap part to replace, I personally think it's better to replace than bother cleaning.

If this was my truck and I had limited means, I'd first replace the MAF.
If MAF didn't fix it, I'd be eyeballing the shit out of my fuel pump and trying to figure out if I had adequate fuel pressure.
If fuel pump is providing enough pressure, I'd probably take it to a dealership for diagnostics, pay them their 2-3 hours, and get my answer.

Actually your bet bet may just be taking it to a dealership and having them run diags. Seems your mechanic may be unable to.

The only other thing that makes sense to me is it could be the TB assembly, but ... that can be spendy.

 

The issue might be the throttle body it’s self, or TPS. The plate might be getting stuck close not allowing the proper airflow for your engine to breathe.

 

As BMF said, these are your codes. I'd replace the MAF, the Hitachi unit is what Toyota used, and the O2 sensors (Denso), the MAF is $50, downstream O2 sensors are $50 and the upstream are $120 (I had no idea there was that big of a price jump between downstream and upstream).

P0031 is bank 1 sensor 1 or or driver's side front one (before the catalytic converter) Rock auto calls it upstream.
P0051 is bank 2 sensor or or passenger side front one
P0057 is bank 2 sensor 2 or passenger side rear one

Our trucks are problematic with O2 sensors so it's not an uncommon repair

I'd also replace the air filter and take a really good look around the air filter box hoses to make sure they aren't cracked or loose.

 

Your coworker is a dink, literally none of those codes indicate a misfire.

P0031 is drivers side forward O2 sensor heater circuit low voltage
P0051 is passenger side forward O2 sensor heater low voltage
P0057 is O2 heater circuit low voltage
P0101 is MAF circuit malfunction
P0102 is MAF circuit low voltage
P0330 is passenger side knock sensor circuit malfunction

First check your battery, once while the truck is off, then again with it running. Sensors can freak out with low and inconsistent voltage.

Check your fuse box under the hood, there's a O2 sensor heater relay that could be bad. If you've never replaced the O2 sensors I'd grab a couple new ones (Denso) and see what happens.

When you replaced the MAF did you use a parts store replacement or get a Toyota/Denso? Aftermarket sensors can be wonky right out of the box.

 

Damn, you're right. I kept saying Bosch, but it was Hitachi. Going back to edit my stuff. Grrr.