2006 Limited NA Coupe 72000 miles. My CEL light came on about 2 weeks ago, car is running fine. First thing I did was disconnect neg battery term for a while then reconnect. CEL went out but comes back on after approx. 3 starts and around 30 miles of driving. I did this several times. Had the codes read at Autozone P2096 & P2098. Took it to O'reillys their scanner couldn't link up. Took it to Advance and they got the same codes as above.
Checked fuel pressure at the fuel rail and it was ~55 psi but slow to recover after revving engine. Replace the fuel filter/regulator no change but recovery was great after revving. Just replaced both rear O2 sensors Bosch OEM no change. Same condition, around 3 starts and 30 miles and the CEL is back. Scoured the net and this forum and not getting any joy as to what it could be. Checked every fuse in the car with a meter, checked all O2 connectors. Checked for vacuum leaks, exhaust leaks all is good. I'm thinking running lean on both banks will fry the cats so I want to get this repaired asap. There is no soot in the exhaust tips at all so I'm pretty sure it's running lean. Battery is original Varta and seems to have no issues.
Have done the me so horny mod, and resoldered the Relay Control Module suspect cold joints about a month ago and really don't suspect the mods to be the issue just throwing it in to cover all bases. Took the RCM out yesterday took a hard look at it and all looks good. Removed all five contacts in the RCM and cleaned the contacts. Only two had a little black from arcing other three looked fine. Metered all resistors in the RCM all good. Put it all back together went for a spin and no CEL. Took her out again for another run and no CEL. My Permagrin was returning. Took her out again this morning and of course the CEL is back on, 3 starts and around 30 miles. Scratching my head here and thinking I will pull the MAF this morning to give it a good look and cleaning. The nearest dealer to me is waaay to far to go to and I trust my skills and this forums skills more than I do theirs. I'm open to any suggestions you guys may have. I have a new crank position sensor as a spare but hesitate to install it as I don't think it would make the car run lean?? Help!!! I want my baby back.
Mark

 

Maybe try some injector cleaner ?
Just a thought.

 

Maybe try some injector cleaner ?
Just a thought.

Ran a bottle through it about a month ago so don't think that would be it. Have also gone through about three tanks of gas since CEL came on two weeks ago so I don't suspect nasty fuel. Thanks

 

Ok try one other thing before you spend a lot money ,yrs ago I had the same thing happen to me , on the back of the motor there is the TB ,you will need to remove the air cleaner box to get to it , you will need to pull out the TB plastic piece and there be kind like a big O ring around that about 1" deep with ribs around it clean this piece up as it can suck air in around it and can give the codes that you are getting ,also check and make sure the muffler is good and tight no leaks , the M112 motor is very sensitive to any kind air leak

 

Osofast, I'm one step ahead of you. Pulled the TB off a while ago, cleaned everything, cleaned maf sensor with electronics cleaner, got some dielectric grease to lube both gaskets/ o rings, checked all vac lines and getting ready to reassemble. Trying to find out how to troubleshoot the MAF with a meter in the FSM before I reinstall it all. No exhaust leaks anywhere. Thanks for the advice.
Mark

 

Gas cap, it may be worn out and not sealing right. A friend of mine had to replace his.

 

Good thought Bill. I have no doubt it's tight I learned that lesson long ago. Could be a worn gasket if it has one? Getting ready to take her out again after assaulting the MAF sensor earlier today. Couldn't find a thing wrong with it but did what I could.

 

Er. Edit - sorry, I apparently can't read whole posts. Ha! Skimmed right over the fuel pressure section.


Failing fuel pump, or bad fuel filter/regulator, restriction in fuel line? I'm *certainly* no mechanic but I look at the obvious from both sides of the equation first: The engine is getting air that isn't metered (vacuum leak, bad MAF), exhaust that isn't measured (exhaust leak, bad O2 sensor) or, since you've ruled those out, fuel needed. In my experience with other vehicles the 3 starts/30 miles is about enough time for most of the OBDII tests to complete.

 

Great thoughts xme, checked gas cap it was tight and the gasket was good. Just got back from a 3 start 40 mile sprint and NO CEL!!! I'm back with a permasmirk right now. We'll see what happens tomorrow.
Thinking that osfast may get the golden wrench award for this one even though I was all over it. If the CEL comes back on tomorrow the golden wrench award will have to be returned
Keeping my fingers crossed, pun intended.
Thanks guys.

 

I would replace the Varta battery as it is very near the end of it's useful life. There are very few still functional and the car is extremely sensitive to voltage degradation. I don't think that it is your problem but at least you would not have any thing else mucking up the issue. Good luck with it.

 

i sent you a pm

 

Just got back from the 5th start and around 55 miles of total test driving and was Greeted with a big fat CEL once again. Open for suggestions???
The battery will be replaced soon, it's not high on my list but I know it will probably fail this winter.
Permafrown is back....grrrrrrrrrrrrrrrrrrrr
Going to stop by Autozone later and have the codes scanned once again just in case it's throwing a new code but pretty sure it will be the same ones in the pic.

 

You never did respond about the injector cleaning. Wanna try that ?

 

Let me ask you this , how is the car running , is it running same with the light on , you may have a ox sensor going out , how many miles are on the car , if the light is a steady light it ok to drive , my car drove fine for over a two years with the light coming on , until I found the leak , and I have had my car going on 9 yrs now ,

 

on the MAF and TB , there is a boot that the MAF fits into it has ribs on the out side or inside , when you put all of this back together it should be a real snug fit , if it not snug air will come in and around it , also look for cracks in the cats this has been a long time issue with this car to

 

Ran a bottle of injector cleaner about five weeks ago, well before the CEL came on. Shouldn't need to do it again I don't think.

 

Car runs great with CEL out runs great when CEL comes on, no difference in performance with lite on or off.. Have replaced both rear O2 sensors two days ago. Don't think mine were bad though. 72,000 mile on car and the light is steady.

 

I had the MAF off yesterday ribbed gaskets are good, gave them a cleaning and lubed them. Seems to fit snug, I really don't suspect them as being the problem. No cracks in cats, did a thorough inspection of all exhaust components, did a thorough inspection of all vac lines all good.

Heading to a friends house this morning, gonna put his Actron scanner on it and also put it on his lift to recheck everything for the bazillionth time.

 

So, you have done everything you know to do, and everything anyone has suggested.

But you also admit the car has the original battery - and you are experiencing what could be described as an odd electrical problem and you STILL won't change the battery?
An old battery can cause all SORTS of troubles with these (and many other) cars.

I'd run to AutoZone and replace that battery now - if it does not cure the problem, you are out nothing, since it is at end of life anyway. Of course, if it DOES cure it - your permagrin is back right away.

 

Mark if you want to meet somewhere and put my new battery in. Take it out a test drive to see if it cures the problem let me know. I am right across the bridge downtown on the river by Yum.