ECU Flash and P0121 Code

Cirrusly Evolvd · Oct 5, 2006, 10:59 PM

I'll try to make this simple to understand with as much detail as possible.

I had my ECU tuned by a well-respected company after installing my new turbo, cams and injectors.

There was an issue with my ECU in such that the tuner could not access any of the tables. Basically it was if the ECU was locked and you couldn't see any of the parameters. The tuner erased my ECU, and loaded the info from another 03 Evo (same year as mine) that was known to be good. He then input my immobilizer code onto this programming. The car starts fine, runs fine and I have no issues with it's driveability......BUT!

Since the tune I've had the P0121 constantly. I clear the code, it comes back within a mile of driving. I did some digging through my trusty

Technical CD and found the troubleshooting guide for this code. Needless to say it all checks out. Voltage, ohms, and range are all within normal parameters according to the Tech info, yet the code keeps coming back everytime. The wires from the TPS sensor to the ECU all check good. I'm stumped.

Any help would be appreciated.

yldMr2006 · Oct 17, 2006, 01:05 PM

DTC P0121: Throttle Position Circuit Range/Performance Problem

===replace the entire circuit..

Kats · Oct 19, 2006, 05:49 AM

when you had the ECU reflashed, more and more manufaturers are requiring a part id to flashed into the computer. I am not sure about Mits, but I do know 100% that 99 VW's to present require computer reflash on installation of new TPS, 03 nissan require in some cases reflash of O2's. More than likely when your ecu was reflashed with another 03 ecu data, not everything went in correctly and it is sensor IDed.

Kats

Cirrusly Evolvd · Oct 19, 2006, 08:31 AM

Thanks for the help on this one but I figured out the problem...I recirculated my BOV. Yup, that took care of the P0121 and P1400. Sounds odd, but from the moment I started the car up with a new BOV recirced the codes have never come back.

Now I have to deal with another problem...P0171 System Too Lean Bank 1 LOL.

4TUN8 · Mar 9, 2007, 01:18 AM

I have both of those codes...I am running VTA.....you're saying that once you recirc'd the bov that both of the codes went away?