ssinister550

iTrader: (8)

i have an 04 gto with LT's, magnaflow catback (cats removed), vrx5 cam and a k&n cold air. it was tuned a couple weeks ago after the cam and has since ran perfectly fine. after some spirited driving last night i got some MIL codes and since it has been running like ****. the codes are p0102 mass air circuit low frequency and p0443 & p0449 evap emissions B.S. i tried to clear them a few times and the evap emissions codes go away but the p0102 keeps immediately coming back. I cleaned the MAF with the aerosol MAF cleaner and same thing nothing changed. it idles almost like its misfiring (rough even considering the cam) and it chops and wants to cut out at part throttle up to like 3k rpm and its runnin pig rich i.e. puffing black smoke and getting less than 10 mpg, and at WOT it runs fine after like 2k rpm. any help would be greatly appreciated.

ssinister550

iTrader: (8)

oh and when coming to a stop (letting off the throttle) idle drops down around 200 and barely stays running

ssinister550

iTrader: (8)

anybody?????

1BAD_LS1 Tunes

iTrader: (8)

do you have a friend who you can swap maf's with to see if it will cure the problem???

ssinister550

iTrader: (8)

yep. i just tried my buddies 85mm maf and it did nothing. same code same symptoms.

bearcatt

iTrader: (41)

Might try checking the Engine sense fuse for starters.

http://www.ls2.com/boggs/dtcs/DTC%20P0102.htm
http://www.ls2.com/boggs/dtcs/DTC%20P0803.htm



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ssinister550

iTrader: (8)

where would i find this engine sens fuse? never heard of it...

fun Pain

also check all your pcm/ecm engine grounds, maybe in all the work that has been done, one of them came off, or is getting a bad connection.

bearcatt

iTrader: (41)

On the GTOs the fuse box is supposed to be down underneath the steering wheel.





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HUNTER02SS

iTrader: (24)

What happend is your MAF failed and when your MAF fails it re-verts to the VE table. Now your car runs like crap because your VE table has not been tuned properly.If your VE table and MAF had been tuned properly you would not notice a difference in the way the car is running when your MAF failed. Whoever tuned the car did not tune it correctly.

Dskeet6

iTrader: (20)

^^^^^ thats what I was thinking...... you should not notice a diff in the way your car runs if your MAF fails.... it reverts to primary or secondary FULL VE feedback..... so if that is off then your car will obviously run like crap.

KRAZY K 2000 TA

iTrader: (5)

i agree with hunter02ss with a MAF code it would go to speed density and run off the VE table so if it is running poorly the VE table may have not been tuned at all.which shouldve been what a good tuner did.

Dskeet6

iTrader: (20)

it could be that the primary VE was tuned with the MAF enabled and ON..... and because your car MIGHT have a secondary VE table the MAF fail pushed the computer into this secondary VE table(which is most likely untuned).

Doc

iTrader: (9)

The 2004 GTO does not have a backup VE table.

Dskeet6

iTrader: (20)

ok..... the car shouldnt run that rough with a failed MAF. check wires and plugs then verify with your tuner.

ssinister550

iTrader: (8)

ok thanks to all of you this is all good info. it was the engine sensor fuse that was blown so the maf was not working. dont know why the fuse blew or why the car was running that rough without the maf but i will get with my tuner about that. put a new fuse in and the car runs fine again. once again thanks guys all input is greatly appreciated.