Put in chipped ecu...now I have problems :(

[B5in]

2001 Allroad 2.7T w/tiptronic

Well I purchased a ECU from a fellow enthusiast with the 3 GIAC programs (stock, performance 91-93 ct., & race 100+ ect.) which came from a working car.

The car really pulls hard & is crazy fast now, but it seems like it's cutting fuel @ 4-5K rpm then kicks back in, sometimes it kicks in & out & in & out. Before & after that rpm range it pulls like a mofo.

here are my mods to help narrow down & tonight I am gonna go to a friends who has a ross-tech vag-com to see if there's any stored codes & to switch to the stock program to see if it still does it.


-Just put in new plugs
-K&N drop-in filter
-710N diverters

I am still yet to remove & inspect the TBB & the accordion tube from the airbox to mani, I did briefly look at them & they seemed fine.

All this started immediately after swapping out my stock ecu & yes I gave the car time to do the TB adaption. I am gonna try switching to the stock program tonight & if it still does it I will swap my stock ecu back in to see what happens then, but I wanted to get some opinions & ideas of what else to check tonight.

thanks,

-Paul

[B5in]

If an ECU wasn't compatible with my car would it even start?

[ColinGruenfeld]

Did you go a range colder for the plugs and ensure proper gap? PFR6Q/BKR6E is recommended for chipped S4's. Also, make sure u gap em at .28-.30. My 2 cents

[B5in]

Did you go a range colder for the plugs and ensure proper gap? PFR6Q/BKR6E is recommended for chipped S4's. Also, make sure u gap em at .28-.30. My 2 cents

No, I got stock plugs & gap'd to .32, could this be the problem? I put the new plugs in a couple weeks before the ECU install & it ran fine

[Muck_and_Grind]

i have the same issue with the boost; my turbos dont spool until about 3 grand; i VAGed mine and it is the drivers side EGT.

[ColinGruenfeld]

No, I got stock plugs & gap'd to .32, could this be the problem? I put the new plugs in a couple weeks before the ECU install & it ran fine

I could almost guarantee you that it is your problem. Whenever you increase boost in a car (which you almost doubled it) you have to decrease spark plug temp and slightly decrease gap. Get the plugs ASAP because it also leads to a potential to blowing coil packs. These "fuel cutting" symptoms you're experiencing is your engine misfiring.

Do it and get back to me with a smile on your face.

[B5in]

Holy 'ish, I am ordering the plugs right now!!! I wish there was somewhere I could just pick them up at :(

[ColinGruenfeld]

Holy 'ish, I am ordering the plugs right now!!! I wish there was somewhere I could just pick them up at :(

I did the same thing when I first chipped my A4 two years ago. GIAC failed to mention the fact that you need to do this for the car to run right... thank god for the audi forums. If I were you I wouldnt boost it too hard in the mean time. Like I said, I blew a coil pack doing that with the wrong plugs. The coilpacks are actually for sale right now on Audizine too! lol Enjoy.

[B5in]

Oh yeah, I am gonna take it easy until I get them in, thank you for the heads up

[Allroad Mat]

I used to have the same problem when I chipped my AR with Revo.... I found out it was the air hose connected to the intercooler are shrinking due to too much pressure all of a sudden! I fixed after changed to Samco.

[B5in]

well here's a bit of an update...


I ordered new plugs ( a degree colder) as people were saying to try that. I switched the program from pump to stock & it ran as it should, but as soon as I switched it back to pump I got the same problem. It kinda seemed like it was trying to switch gears @ 4K during WOT & then it freaks out & down shifts back. The trans isn't slipping, it just tries to shift too early. Do you think I have to get a GIAC tip chip?

Also there were no faults at all when I checked with vag-com. I still haven't checked the hoses carefully yet, but it just seems that it's shifting gears back & forth like the TCM is confused. Any ideas?

[A62TURBO]

I would never install a chipped ecu from another car.

[///M3 TO S4]

I would never install a chipped ecu from another car.

....why?

[B5in]

....why?

X's 2


It came from an exact year & trans as mine

[A62TURBO]

Why go through the trouble of swapping out the ecu when you can just flash it.

[B5in]

Why go through the trouble of swapping out the ecu when you can just flash it.

because it was $400 cheaper & is plug & play. The ECU is fine, something else is wrong, even if I sent in my ECU to GIAC & they flashed it I would still have the same problem & $400 poorer, it just seem like something is giving out because of the extra boost because when I switch it to the stock program it is fine.

[agoltz]

Change your shift program to 00032 using vagcom and recoding the tranny.

With all that extra power esp torque you need tp be careful with the tranny.

In the 2002+ you have Sport mode which makes a big difference

Id get the tichip

but make sure that you get a samco TBB as well

I did what you did and did not change anything with the sparkplugs - I hate to say it but I think its a more basic problem - tranny shift program.

[B5in]

Change your shift program to 00032 using vagcom and recoding the tranny.

With all that extra power esp torque you need tp be careful with the tranny.

In the 2002+ you have Sport mode which makes a big difference

Id get the tichip

but make sure that you get a samco TBB as well

I did what you did and did not change anything with the sparkplugs - I hate to say it but I think its a more basic problem - tranny shift program.

Doing that tomorrow, thanks for the heads up, I hope that fixes it

[2000Pound Geico]

man when it comes to ecu upgrade you must not go cheap!!
for our cars ecu upgrade will set us back around $500 to $600 bucks!
the best thing to do is send the ecu to a pro-shop along with all the upgrade you have done to your whip!!!

[B5in]

well the TCM recode didn't fix a thing, but when I was in there I pulled a code finally:

16805 - P0421 Bank 1 Efficiency Below Threshold


which can be either the o2 sensor or CAT right? I still want to get my new plugs in, but would a bad o2 sensor cause the car to act like that?

[KTG]

I bought a Revo ecu off Egay a year ago, and it runs great! Feels better then stock all around. I too have felt a hesitation around 4-5k sometimes. I've done vacuum test, plugs, fuel filter, TBB, o2's, dp's...Its not every time I boost, just once in awhile. Not sure what it is....I chalk it up to the fact its a 8 year old car which still boots out 300+hp! F-it its fast!