I'll try to be as thorough as possible...

Bought a used 2k2 auto max with 40k 2 weeks ago - ran like a dream for a week. Then, one morning on commute to work, it felt like I was driving a 4cyl. That crisp/peppy throttle response was gone - now i push gas and wait to accellerate. If I push far enough, trans downshifts and I go - but it used to have more power w/out downshifting. No SES light at all. When I got to work, I pulled 0011 and 0012 codes via the ignition/gas pedal push method(variable intake timing? - both banks). I reset ECU to see if they returned, and they have not. I've been driving for a week now, and no new codes.

I read up on the MAF problems, and people describe a 2500 wall. I can still go past 2500 - up to redline even if floored, but somewhere between 2k and 3k the accelleration slows during normal driving - I have to push pedal further to continue accelleration. The power loss seems to be across the entire RPM range though. Under WOT, she still screams, but my butt dyno is telling me it's not as good as it was.

I ordered a MAF from Dave B (ordered the 2k1 maf sensor only instead of the $$$ 2k2 maf and tube assembly. Will swap IAT in before replacing MAF) - awaiting arrival next week to hopefully clear things up. Just wanted to see if anyone had any other ideas.

Two more things to consider - I have some black soot in my tailpipe - not excessive, but its there. Just noticed tonight, don't know how long it's been there. Could this be indicative of any problems? The other might just be mental, but it sounds like my exhaust note has changed a tiny bit - The best way I can describe it is it sounds a little like my wifes 98 with a Ypipe. It sounds like I can actually hear the individual engine revolutions - not loud like an exhaust leak - but just not the silky smooth note that there was.

Think that about covers it - sorry about the rambling format, just trying to put down everything I can think of.

Looking forward to any ideas !!!

 

hmmm. The auto-trans can be reprogrammed. Check if you have that TSB done (comprise of later MAF sensor & auto-trans reprogramming).

Where did you get your car from? I hope it's not your case but an engine that had been abused by previous owner, especially w/NOS, will causes excessive wear to the internal parts of the engine and transmission.

 

The car is bone stock - no mods ever done...seems to be in pristine condition. Just seemed weird that the change in the car's demeanor was essentially overnight.

I bought from a private seller - married late 20's couple.

I know the MAF TSB wasn't done, as it still has the old MAF in it. Could prob stop by a dealer to see what recall/TSB history they have on the car.

 

wats the tsb????

 

Try getting a Petro-Chemical cleaning done at your local dealer. That will remove alot of dirt, etc from the engine and usually helps with performance.

 

2 weeks ago, I bought a 2002 SE with 60K mi. I test drove it and it was ok, but not as powerful as I thought. After I talked to their mechanic who he seemed very knowledgeable, I did a fuel injection cleaning at Pep Boys (I know I took a chance with Pep Boys) using the high presure bottle method for $69.95. I think they bypassed the fuel tank and hooked up the FI cleaning bottle to the fuel rail somehow. It was done in about 45 minutes and boy did it transformed my car. This car is amazing and a blast to drive now. Maybe that's your problem. I also hear that there are gas quality issues in the Mid-West...with a high number of clogged fuel injectors...so bad fuel could also be an issue.

 

update: On the way home from work yesterday, the ses light finally came on. I pulled a code 0172 (fuel injection - too rich...that fits with my black soot on tailpipe). After much reading, it seems the MAF sensor (along with o2 sensors) has a role in determining the A/F mixture, so I'm hoping I'm still on the right track. I cleared the code to see what else I would get.

On the way to work this morning, the car pretty much went into limp mode. I finally got the 2400 fuel cut, and had to limp the car home (no ses light). The 2400 limit would come and go...sometimes I could go over, other times I could not. Even when I could, it was a very sluggish/jerky/overall unenjoyable driving experience. Got home, and checked codes again, only to get all 0's.

MAF should be here tomorrow, so I'll slap it in and keep my fingers crossed.


shift_replacemaf

 

Sorry for bringing this thread back, but did you find a fix for your car?

Mine seems to have similar problems now.
2k2 six speed, 80K miles. I've noticed it had been kinda sluggish lately, but untill today my tailpipe has been clean, now there's a black deposit (soot) in it and the car really has a lack of power.



I don't think it's a MAF, it failed at 60K and was replaced with 2k1 maf, and it has been running fine until recently, plus the simptoms i had when my original maf failed don't much to what's happening now. I'm thinking maybe it's 02 sensors but no codes in the ECU. Could 02 sensor not be working properly and not throw a a check engine light, no pending codes either?
Thank you for all your help.

 

Does a 2001 MAF work in a 2002? What does the 80 bucks versus 480 get you in the 2002 version?

 

ABAKLEN what kind of Exhaust is that??

 

Looks like frankencar to me. Excellent choice. I have the same.

 

Looks MEAN i like

btw JASONB hows the fitment of the knock off rear valence?

 

LLLLLike a ggglllove! Its not too bad. Its not perfect but definitely worth saving your $$. Back on topic....
I'd say something is definitely off cuz it seems to be running rich with the soot. Unless of course you're driving around at about 5k rpms all the time cuz from what I heard our 5.5's run really rich in the high rpms.

 

My car has had a sooty tailpipe since new and it has always pulled hard. I would be worried if it was greasy in the tailpipe, but if it is dry there's no need to worry. Your problem is the MAF IMHO.

 

thanks 99 SE-L and Jasonb1982, i like my FC exhaust too...
i used to have Greddy, but it was too loud for my taste (it was on a car when i bought it). Franken car catback is stainless, and it doesn't hang low like Greddy, the muffler tucks away neatly under the car

Jaws, i don't think it's a maf, i just did seafoam through vacum line and also put some in the gas tank, and car runs way better now, i'll wait until about 500 mi before oil change and i'm gonna add some seafoam to the crankcase, and some more through the vacum line. By the way when i did it, there was a lot of smoke coming out from the tailpipe

 

I think I have this same problem...maybe its all in my head:
"That crisp/peppy throttle response was gone - now i push gas and wait to accellerate. If I push far enough, trans downshifts and I go - but it used to have more power w/out downshifting. No SES light at all."
I am pretty sure my car use to have better accelaration at 2000-2500 RPM. Now I have to hit the gas harder to get it to accelarate and when I do that it revs up to 2500-3500RPM. I'm afraid it might be the Transmission but I have my fingers crossed. Hopefully its something like a MAF sensor. The SES light is not on and I didn't tell my mechanic because if you didn't drive it before you wouldn't see the difference. Someone else that I know said that it might be because I am driving in over drive and to turn it off in the city (improve acceleration). Could that be it?