jak2908

iTrader: (1)

I have a 2000 z28 a4 which is pretty much stock, and i have this slight hesitation right around 2500-2800 rpm on acceleration and i have not a clue what it is, i definately notice it in second gear when i'm about half throttle and up, its not really a bog just a hesitation that last about half a second or so..

Thanks for the help

01ssreda4

iTrader: (96)

Likely O2s but you need to do some diagnostic first. But if they have never been replaced they should be replaced anyway IMO. Moving to GM.....

LS6427

iTrader: (2)

And if they are 02 sensor(s).....PLEASE don't get ripped off at the dealership for them....get them at Amazon.com

Denso brand......Part # 2344025 16 inch wire. They work in all 4 02 sensor positions. $33.00 each. Just zip tie the extra wire to the frame.

.

bobbyd

iTrader: (10)

i have the same problem. o2's were changed a few months back. when i get the hesitation my aeroforce gauge reads KR. between 2-4. dunno if its false KR or what

jak2908

iTrader: (1)

i have someone of a cheap scanner that live feeds, so i suppose just watch and see if the voltage gets irratic on the o2 sensors?

OSU Football Fan

iTrader: (23)

I had this problem once & it turned out to be a dirty MAF sensor.
LOL, one of the joys of owning a K&N air filter.

Take some electronical cleaner & Q-tips & clean it really well.
Make sure the small wires are clean & free of oil.
Just be careful not to break them.

jak2908

iTrader: (1)

Frick... I have one too..

OSU Football Fan

iTrader: (23)

Yeah, K&N air filters have a tendency to get oil on the MAF sensor.
I had a very similar hesitation at around 2500 rpm.

Get a can of CRC electronic cleaner. It comes in a red & white spray can.
Soak the MAF sensor thoroughly & clean the wires off with Q-tips.
It worked like a charm for me.

Good luck man.

LS6427

iTrader: (2)

^^^^

Just so people know.......be careful touching the tiny little wires with a q-tip.......it can break the wire and then you'll be buying a new MAF. If you get a can of CRC MAF cleaner and just blast the spray directly into the MAF through the screen, real good, it will clean everything off that might be there.

.

bobbyd

iTrader: (10)

mine wasnt the MAF. i cleaned it and even got a new one and still happens.
hopefully the TS can get his to work

Snake_Skinner

iTrader: (12)

Thanks OSU FF, im cleaning my damn maf this weekend. I too have the hesitation RIGHT at 2500 rpms in every gear and any throttle pressure along side with a k&n air filter, god i hope this helps. really hate when my car isn't running 100%...