[///Mspired]

My car has been throwing the above code. The noticeable issues with the car consist of the following:

When I let off the gas the RPM drops really low then immediately revs back up to where it should be.

The car sputters sometimes while accelerating.

Occasionally the car at idle will start shaking and act like it's about to die, it's fine if I gas it or throw it out of gear.


Any thoughts? Anybody else ever had this problem? I replaced all 6 plugs and the lower intake boot. I still have a new fuel filter to put in and I have a new CCV system on the way.

 

[///Mspired]

Nobody has had this issue?

 

[dmax]

Not sure whether the M would have different causes, but this sounds like an ICV issue, which on my non-M, I'd just clean with a can or more of carb cleaner...and get the TB while at it.

On yours, cleaning TBs is a bit more work!

Also, fuel filter might be a big part of it, especially if it's been many years...and then, only thing I can think is that you still might have some air leaks around, beyond just from the lower intake boot. If the stuff you do doesn't fix things, consider getting intake smoked.

Techron is always nice too...and hard driving even nicer!

...and a bump for you!

EDIT:

Oh, and disconnect battery, remove MAF carefully, and clean it. You don't have an oiled air filter do you?

Actually, you could also disconnect the maf and see if it runs better...that would indicate more an issue with maf or air leaks.

 

[TxZHP04]

Could be lean, could be rich. Based on your symptoms, sounds like it might be lean. This would imply either too little fuel or unmetered air entering the intake after the MAF. Clogged fuel filter or weak fuel pump could cause fuel issues. Without testing fuel pressure and flow, we can't say whether you have a fuel delivery issue or not. There are lots of places for air leaks to occur. Without a smoke test, we can't tell you where this might be. Replacing the lower intake boot and CCV might fix it, might not. Also possible but less likely would be a faulty MAF and/or O2 sensors giving erroneous readings.

Basically, what I'm saying is that without further diganostics we can't pinpoint your problem beyond the fact that the codes are telling you that your AFR at least appears to be out of spec on both banks.

 

[///Mspired]

Thanks guys.

The problems started after a long track day a few weeks ago. Since then I have replaced the intake boot and plugs. I will do the fuel filter when I have free time, I will clean the ICV when I replace the CCV system. If I have problems after that I may just have my tech look at it.


I cleaned my MAF when I replaced the boot. I will try unplugging it though.

 

[///Mspired]

Replaced the fuel filter today, next on my list is the CCV system.

 

[Andy2108]

Did the new fuel filter help at all?

I think your off throttle rev dip problem is transmission related. Maybe its time to consider an ATF flush?

Could be lean, could be rich. Based on your symptoms, sounds like it might be lean. This would imply either too little fuel or unmetered air entering the intake after the MAF. Clogged fuel filter or weak fuel pump could cause fuel issues. Without testing fuel pressure and flow, we can't say whether you have a fuel delivery issue or not. There are lots of places for air leaks to occur. Without a smoke test, we can't tell you where this might be. Replacing the lower intake boot and CCV might fix it, might not. Also possible but less likely would be a faulty MAF and/or O2 sensors giving erroneous readings.

Basically, what I'm saying is that without further diganostics we can't pinpoint your problem beyond the fact that the codes are telling you that your AFR at least appears to be out of spec on both banks.

He brings up alot of good points.

A smoke test is $100. That may be worth it to see if you have an intake leak.

A fuel pressure test might also be in order after your new fuel filter is installed.

 

[///Mspired]

Fuel Filter did nothing. Next is the CCV. I doubt it's a tranny problem as the shifts are crisp and I am throwing a code for bank 1 and 2 mixture preparation. I'm almost at 90k and I make 1 mile trips almost everyday, also another reason I think it's the ccv system. That and slow oil loss over time.

 

[Andy2108]

But what does the ccv have to do with fuel.

I still fully belive that you should do seafoam to clean up your injectors and stuff.

fuel pressue test too