Jmac29

My buddy has a 99 z28 m6 with 83k on it, only mods are slp loudmouth catback and a descreened MAF. We ran a code came up as the 02 sensors after the cat.

When driving the car it hesitates like crazy between 2 - 4k rpm .. could this be the 02 sensors?? Ive read its most likely the MAF but i really have no idea.. Please help!! Thanks guys

blk/slvr02ss

iTrader: (21)

Well just switch it out w/ yours and u will know if it the MAF or not !

WhiteKnight '01

Did you keep the cats on with the SLP Loudmouth? That could affect the codes.

Just my opinion, but a descreened MAF is bad idea, **** can get in there.

Jmac29

the cats are still on the car it has the stock y-pipe.. where gonna try switching the mafs see if that narrows it down

00_Trans_Am

Change the MAF, you can thank me later.



Seriously though, mine was doing all the same ****, throwing CAT and O2 codes and I replaced both cats and all 4 O2's until I read about the MAF problems, replaced my MAF and my car is back to being an animal.

blk95formula

I agree descreened MAF is probably causing the problem

blitzace12

iTrader: (1)

Sounds like a clogged cat. Do a pressure test in the pre cat 02 sensor hole. Relativly any pressure when you rev it = clogged cat. Any rattlling?

Snake_Skinner

iTrader: (12)

Old i know but hey Jmac if/when you switched out maf's did it resolve this problem?

Just noticed my car has a slight hesitation everytime RIGHT at 2500 rpm's, i know one of my cats is good bc it got replaced by warranty but not sure about the other but i dont hear any rattling, also i do have a descreened maf and have never cleaned it really.

Drag0

Did anyone ever figure this out same problem here. I also got lt's and my car has a hesitation around 2500rpm to maybe 2700rpm. Checked the plugs, wires, maf appears to be clean(no dirt stuck in it ) Im thinking its either the maf or 02 sensor. Can anyone who had this problem please help out

red_00z28

iTrader: (14)

unplug the maf and take it for a test drive. Had this problem. Ended up being a dirty maf.

Redlined2000SSLS1

Do you have a K&N or any other oiled filter? I had the same hesitation in my SS. Cleaned the MAF and replaced that piece of junk filter and it's a different car. My dad is a GM tech, he said that he has seen that over and over again with K&N air filters.

Drag0

guys i figured it out it was a dirty maf sensor. The damn k&n filter caused it
Thanks for the help appreciated it

BlkZMD

That's crazy, I would have never suspected the air filter.

chrysler kid

iTrader: (14)

I am against k&n for that reason.

I also prefer cleaner air than more volume.