No CEL but reader says it’s on. Emissions not ready

Hey, I hope this isn’t a scenario that’s beat to death. I could not find this exact scenario searching the forums.

I went for emissions 6 weeks ago to find out the dome light fuse was pulled and my system was “not ready” fast forward to now and I’ve replaced the fuse and driven it 600 miles, only 200 of which since my most recent system reset (radio install) and I have system not ready.

I’m getting conflicting info from mechanics and emissions guys.

I’m being told the 02 sensor code is not an issue until my system is ready. Some forums show weird issues with bad 02sensor causing the system to be “not ready”

I’ve never had a CEL, and it does have a functioning bulb. I’m getting typical gas mileage. And the engine sounds great as far as I know. I bought the truck and it had a recent engine put in it. But passed smog in PHX AZ before I bought it.

just keep driving it? Hopefully the dmv lets me renew my temp tags tomorrow.

 

Invest about $25 in a bluetooth OBD2 adapter and the Torque Pro app. Helpful troubleshooting tool and you can see if the emissions tests are pending or completed.

Your check engine light should be functional as it's an LED soldered to the board.

200 miles since a battery disconnect should be more than enough to complete all the system tests. Go to your local auto parts store and have them use their OBD scanner to check if they're complete.

If the tests are complete and no pending or active CELs, go get your emissions test done.

 

Ok. So how much longer do I need to drive? I have a obd2 and I get the same result as the emissions place last night.

 

It's less about how long you drive and more about how you drive, whether you reach operating temp, how long you stay at operating temp, whether you reach closed loop.

The system itself is trying to gauge a lot of things. It's measuring cat temps both pre-cat and post-cat when hot and cold. It's verifying filtration is within a specific range through the cats both when cold and hot. It's validating output of the O2 sensors when hot and cold. It's checking SAIS function at startup to ensure temps rise as expected. It's needing you to drive long enough for EVAP system to confirm it can build vacuum, hold enough vacuum to function, and purge vacuum from the system once enough gas is pulled from the tank, which means you need to either drive long enough to deplete enough gas to trigger that situation. That's just touching the tip of the iceberg.

There are some constraints. Like, you MUST be able to enter 'closed loop'. Failure to reach closed loop will result in never reaching readiness, IIRC. I remember this is something @Tundra2 was struggling with on Crackhead (read up). I want to say his issue may've been related to his t-stat and a bad ground, but I don't recall 100%. Maybe @empty_lord would have some juicy input here, if he has a minute to share.

Without knowing how you're driving, without knowing if you're reaching closed loop, it's tough to say when it could happen. But you're not the first person on here I've seen struggle. All I can tell you is, because of this pesky P0328 knock sensor code I throw when it's cold out, always once within the 1st mile of a trip unless I stay below 1750rpm for the first 2-4 minutes of my drive, I need to clear my codes regularly. I typically hit readiness pretty fast, and I get there with a combination of 10-15 mins of stop-and-go on surface streets, 10-15 mins of being on the interstate, and another 10-15 minutes of stop-and-go. Sometimes I do one more iteration of interstate with stop-and-go and I'm at full readiness. Typically doesn't take more than a day, I always check before I clear codes.

 

Man . . . @shifty` is the man !
I was gonna 'attempt' to post something similar . . . but so glad I didn't as it would've been an embarrassment. LOL

So here's the shortened version . . . I had a recent code issue at emissions . . . the tech there handed me a printout he keeps for customers. It was a 'Generic' explanation of cause/ remedy for many cars/ trucks. Long story short it said to get out on the highway and hold speed at 50 mph for 2 miles, then increase speed to 60 mph and hold it there for 2 miles, then increase speed again to 65 mph and hold it for 2 miles. He said it was important to hold speeds close to 55. 60 , 65 as much as possible for the 2 miles. He said to repeat this process on the same 'trip' as much as possible.

Now I have ZERO clue how much this guy does or doesn't know, or if this even makes any sense . . . but I did what he said for about a 120 mile round trip, then came back, and it cleared up all the codes except the the SAIS code I was having trouble with. But that's a story for another thread I'll post up soon.

 

I dorked around with this issue and solved this on a Tacoma and Hyundai Accent. You have to Google the READINESS MONITOR DRIVE PATTERNS for your truck. However, since you don't have a MIL it appears you have a pending P2241. I don't think the system will run with a MIL or pending code. You will need to solve the P2241 before you proceed further as all 4 of your main tests show not ready. Normally inspection stations will pass you with one not ready (depending on state) but I found "Evaporative System" is the last one to go out.

This was what I used to get the Tacoma to green light and ready for evap system.

 

Ah damn, I missed that box with P2241 up there, good eye @Tunrod.

If the code is pending already, 90% of the time, it's going to set IF the truck can reach readiness. It's for the O2 sensor after the cat on the passenger side.

I looked up your truck @Primakluk and your downstream sensors are the same part number, which gives you easy diagnostic options. Here's your OEM sensor (Denso brand) on Summit Racing, and RockAuto which are the only two vendors I'd buy from, since scAmazon and fleaBay sell counterfeits like it's going out of style.

Two options to troubleshoot the sensor here.

• If the wire harness is long enough, as stupid as it sounds, you can swap the plugs from the passenger sensor to driver sensor and vice-versa.
• If it's not long enough, you can unscrew the sensors and swap one side to the other.

If the code changes to P2238, you know the sensor (the one that is and/or was on the passenger side, depending which option you chose above) is bad. If the code remains P2241, you have an issue elsewhere, in wiring/ground or otherwise. Any local auto parts store can scan codes for you.

While you really only need to replace the bad sensor, I always recommend replacing the upstream on the same side as the downstream, since they work together in pairs, and if one guys, chances are the other isn't far behind, and when the upstream goes bad, it can cause all kinds of fuel/ignition related problems.

 

Oh, and here's your upstream sensor at SummitRacing and RockAuto. One on each bank.

I prefer Summit because usually they're free ship over $75-100 and their customer support is 2nd to none. Rock will show you a lower price, but the shipping usually pushes the price up, even with the 5% off coupons you can get at RetailMeNot.com

Upstream are often a bitch to get off. There's a cheap tool at the auto parts store to help break them free. If you're in the a road-salt area, you may be in for a world of pain. But other than busted knuckles, it's a simple plug and play job usually for me.

 

As stated above dig into the code. Any emissions related code will effective stop monitors from running any further in the affected system.
Past that there is certain drive cycles to get monitors to set, there is also a “check mode” that can be enabled by higher dollar scanners that’ll make the monitor check single step. Once entering that mode it’ll clear all current monitors but within 1 proper drive cycle with all the criteria met for every monitor it’ll all set faster.

 

Thanks everyone! holy cow, you need to create a course for this stuff. I always got lucky with my 4runner. I will tackle swapping sensors this weekend and see if the code changes or persists. The emissions guy told me the code could go away once the state was "ready" so I was holding out for that but it sounds like I need to be more proactive. I will report back once I have some results this weekend. The PO didn't really take care of this truck so I'm slowly finding all the issues and fixing them. (burns oil, oily substance from a/c compressor, PS fluid reservoir leaks, myriad of other problems I've already fixed) I'm slowly getting to all these, but getting it registered is priority.

I have a cheap reader at work I'll take home for the weekend and see what I can see.

 

The refrigerant in your A/C system is essentially an oil. Probably blew a seal in the compressor. A/C is one of two things you never want to use a "generalist" shop for, seen an automotive A/C person unless you have the ability to reclaim refrigerant, vacuum lines, and leakdown test.

These trucks usually don't burn oil, the valve covers are notorious for leaking, either because the bolts are only hand tight (they'll snap if you overtighten) or because they shrink with low miles or age.

PS reservoir clamps, I've seen, can be a cause of leaks.

 

I can't find a drop of oil on the whole block, It seems every time I check the oil I'm a qt low (every 2 weeks). Plan is to do the PCV valve at some point. The motor was replaced on this truck at 345k and the motor has 150k on it. I can't say they did a good job on the swap, they used original parts from the other engine aside from: plugs, denso coils, and a timing belt kit. The block was cleaned and maybe painted below the valve covers and its dry as a bone. Its an AZ truck so no rust anywhere.

The A/c leak is right on the bottom and it just gets wet a few days after I clean it, so It hasn't dripped yet.

I did read that about the reservoir clamps, it does look like that.

 

As you know, oil doesn't just disappear. It's either getting burnt in the exhaust or it's leaking/pooling somewhere.

Compression test would be high on my list of things to do, before you sink a lot of money into it.

 

Ok all,

I did the 02 sensors on the passenger side one at a time just so I could isolate problems, but after replacing the upstream passenger side no more issues. The modules were all ready after a short 20 mile drive and I just passed emissions. I went ahead and did them all because I don’t want to get under there again.

Thanks everyone for the info, the drive cycle stuff helped me get the readiness much quicker.