jas3113

I have a 1998 A4 1.8TQ Tiptronic

Just bought a used APR Chip with ECU and installed it yesterday. Now if I step on the gas or if I let off the gas from a high RPM the RPM will drop below 500 RPM and will search for a second or two, before settling back at 800 RPM or it'll just stall.

I just called APR hoping for some insight, but instead got "we do not support items you got used". So off to the boards for answers.

I'm still new to Audi, I did some searches already, but came out with no answer.

The ECU I bought was from a 99 1.8T with Tip, but the box ended with a "P". My box on the car ends with a "C", could that cause the low RPM/stalling?

I did the TBA two times, the first time, right after installing the ECU, I forgot I left the AC on and put the car into start position, but turned about 30 secs into the TBA.
Second time I did it, I disconnected the ECU for about 10 seconds and redid the TBA. (was 10 seconds long enough?)

The car feels completely different with the new ECU, but searching the board and seeing other things that can be wrong, I needed to question to see if that could be the culprit.

The car has 118k on it.
I don't hear a "honking" sound from the BPV, but could a defective BPV cause the problem?

The car get about 225 miles per 13.5 gallons, car takes a bit to start and was laggy prior to the ECU swap, could the MAF or O2 sensor have gone bad and not throw a check engine code?

This didn't happen with the original ECU and I have not swapped them back yet to see if the problem is fixed.

TIA for any input.

John

BSCA4

Did you bought it off a manual car? If yes, you may need to recode for TIP.

jas3113

The ECU from from a 99 1.8T with Tip

VTB(Erik)

you should be good. I'd try swapping in the old ECU to see if the problem persists (since it takes all of 5 min). You can hear the TB clicking during a TBA, make sure that's stopped before starting the car. I usually let it go for a few minutes. A bad BPV won't stall your car at idle. Your gas mileage is pretty low, I get around 20 in the city and 30 highway. The hard starts and bad mileage means that you're probably running rich.

BSCA4

plug in the new ECU, turn the key to start possition (but DO NOT start), wait 1 minute (you can actually heard the TB doin it stuff very neat , the motorized sound), after it stop start the car but do not touch the throttle for a few minutes. And then it take about 1 to 2 days before it;s fully adapt (my take about a few drives (start and drive) before the idle stable. BPV is a must to upgrade as your car had quite a few miles.

jas3113

I'll try to figure out the gas mileage after this is resolved.

John

BSCA4

Your BPV may need to be change

goldringer

TJ: Can you recode a 01 FWD Tip to 01 Quattro Manual, both M box?

Alpha7

switch up the soft code... I had to do it w/ a used M-box X Chip I purchased.

jas3113

Just an update the car stopped stumbling and RPM seems fine. Ordered a Billet BPV also.