4.7 limp mode

Could anyone help me out I was driving and got almost to 60mph and it slammed and lost power, rpms would go up but didn’t help it

 

Any codes? Theres 100 or so sensors. Recent work done?

you’re gonna have to dig deeper.

 

Gonna need to get the codes read. I went into limp mode in my 06 about two months ago. Truck was driving fine, then at a stop light it started idling low and CEL came on. Red light turned green and the truck wouldn't berely move

 

Were here to help, but… right now, the best we can do is say, yea you can fix that. And not really mean it, cause…i dunno either.

 

Need more info. Doesn't sound like a limp mode. Sounds more like a transmission failure mode.

 

Missing the most basic info. Which engine? 2WD or 4WD? Different transmissions. Really hard to give any comments or places to start without that.

 

Assuming it's an automatic here, the V6 and the V8 were the same transmission Aisin A340, plus the title says 4.7L, so we know it's an auto A340 4 speed

 

om gonna wing a guess at clogged cats, bad gas, or a bad ground somewhere.

 

Ha! Not sure how I missed the engine in the title!

 

@Lanemc explain "lost power", like it won't move, at all, or it's difficult to move.

With limp mode, the truck won't shift above 3rd gear and runs like shit. Clearing the code will help until the code sets again. Need to know what the code is before anyone call tell you what it is.

If you heard a loud bang out back and the driveshaft isn't spinning, then the 2000-2002 are known for having a weak planetary which likes to grenade abruptly. If you heard that and you rev but the driveshaft is spinning, then you either just blew your rear end or pinion.

Get us three things:

1. Codes, if the check engine light is currently on
2. Tell us whether the driveshaft is spinning
3. Tell us if you're 2WD or 4WD

 

My experience with limp mode in my Tundra has been a CEL for a knock sensor. When that light comes on, getting the truck to even 35mph is a major chore. I recently had to drive to move a mattress for a family member, drove it with the code reader hooked up so the light could be cleared if it popped on. Yeah, I know a rodent got under my intake and chewed up some wires (confirmed with a borescope camera), just haven't had the time to get to it yet (not my daily driver).

 

I think I mentioned, but we're in similar boats. P0328 here. But no chewing. I suspect one of two things, since it's super random and only happens within the 1st mile of driving (also requires two consecutive trips with same event in order to trigger). I've either got a loose/faulty connection on one of the pins and/or the harness connector is loose, or the knock sensor is on its way out. Either is feasible. I need to look into when it happened. I'm wondering if the alternator burning up may've impacted the sensor upstream. But the code pops so infrequently for me that it hasn't been high on my priority list. I've always got the wireless OBDII dongle plugged in, so if it ever does come up, I confirm the code and clear it and the truck is instantly back to full function, and the code never returns, usually for weeks or months.

 

I just know I saw a rodent nest under my intake with the camera, maybe even a dead mouse. I'm assuming the wires are chewed. My P0333 code pops on most often on start up, or within 2.5 miles of start up. It is certainly quite annoying and it has popped on in really inopportune times before. I've parked the truck until I have time to pull the intake off, hopefully this weekend.

 

OP tossed a frag grenade in here and bounced out.

 

Nah, thet NEVER happens...

 

Says the Fragman

 

Yeah, CEL codes would be nice. No matter the code, for the 4.7 I recommend a SAIS bypass.

 

Gah, seems like so much more hassle than it’s worth. We have more people coming in here bitching about still having problems after the bypass than we do people using it. So much so that I honestly would just replace the damn pump and valves and be good for another 20 years.