Thread: Any Newbie to GTP tuning tips, as far as what NOT to do??

My son loves his new 2001 GTP Special Edition.
Only mods are a gutted cat and a cold air kit. The cat was evidently gutted by the previous owner, or simply has come apart, but regardless, we get a P0420 code.

I bought the credits needed for my HPTuners setup, so I can take care of that code, hopefully.

I don't want to just start clicking keys on the laptop and calling it a tune, lol, and I will be doing some datalogging so I can check over the KR and Fuel Trims and adjust as needed.

I don't want, or expect anyone to tell me HOW to tune this car, but I'd appreciate a head's up on any of the things that I should be aware of, or any things that I should NOT change.

I know on my Camaro and truck, torque management reduction or elimination was a given, but read here that most say not to do that on these cars...so that is what got me thinking that a good idea was to simply ask for a little help as to "WHAT NOT TO DO"...

He does run 93 octane and the only mods are the mentioned cat gut-job, and cold air kit. I just want it to be both safe, and optimized, as no vehicle is both from the factory.

Thanks in advance...

You will either need to live with the SES light for the cat, or you will need to stop the cat diagnostic test. Otherwise, the car will run rich while cruising.

HPT doesn't have the ability to remove the test unless they added it since they updated to 2.23.

Something else to change in there...which is simple...

Fan turn on points...have them kick on way sooner. Keeps things quite a bit cooler.

Originally Posted by GTPpower

You will either need to live with the SES light for the cat, or you will need to stop the cat diagnostic test. Otherwise, the car will run rich while cruising.

HPT doesn't have the ability to remove the test unless they added it since they updated to 2.23.

Or use this http://shop.zzperformance.com/store/...-Emulator.aspx

Originally Posted by GTPpower

You will either need to live with the SES light for the cat, or you will need to stop the cat diagnostic test. Otherwise, the car will run rich while cruising.

HPT doesn't have the ability to remove the test unless they added it since they updated to 2.23.

I actually have the newest version, which is 2.24, but honestly have not looked at the program since downloading his stock tune so I could license his VIN.

But, I was going by this:
http://www.grandprixforums.net/remov...ml#post1032043

Found in the top sticky on this section. It looks like I can have the sensor functioning, but simply turn off the SES light and it would do the CAT test once, fail, then ignore. Is that not right? or am I still fuzzy on that whole 9 page thread?

Originally Posted by blueguy

Something else to change in there...which is simple...

Fan turn on points...have them kick on way sooner. Keeps things quite a bit cooler.

Yes. That will definitely be done. Don't have my truck's fan temps on this computer at work, but I will set them at the same temps as it is, which has worked well. Thanks.

Originally Posted by Explicit_Spade

Or use this Easy Performance - O2 Emulator #EP-O2SM-GM01

Thanks for the link. If what I asked above is not going to work, then I guess this will be the next option.

Originally Posted by PeezDaddy

I actually have the newest version, which is 2.24, but honestly have not looked at the program since downloading his stock tune so I could license his VIN.

But, I was going by this:
http://www.grandprixforums.net/remov...ml#post1032043

Found in the top sticky on this section. It looks like I can have the sensor functioning, but simply turn off the SES light and it would do the CAT test once, fail, then ignore. Is that not right? or am I still fuzzy on that whole 9 page thread?

I have never checked to be sure that actually works. I don't think it does, but it would be worth a try.

Where would I "hijack" a TinyTuner file at?

Here is where you can download it.

ClubGP Message Forum troubleshooting

Pretty sure im running a 2000 GTP .bin file in my car and dont have this problem. Mines a 2001 GT.

So leaving in both o2 sensors and setting the p0420 code to no mil or whatever and just allowing the test to run and fail like it says in that 9 page stikied thread doesn't work?

Originally Posted by 98ctd

So leaving in both o2 sensors and setting the p0420 code to no mil or whatever and just allowing the test to run and fail like it says in that 9 page stikied thread doesn't work?

That's what I am reading too....

Yea that's what I was asking. When the PCM is stock and the car is stock, how many times does it run this test? My understanding is that it runs it a few times a drive cycle. So what's the difference if it runs it and fails a few times a drive cycle and it doesn't set any codes or it runs it a few times a drive cycle and it passes and doesn't set any codes. Or does it run once and if it passes not run again? I'm not trying to fight with anyone I'm new to this 3800 tuning thing and would like to be able to run no cat or hi flow cat and not set the cel if possible. There's lots of theories but no definite answer.

Buy 2 spark plug non foulers for 6$
Drill threw one with a 1/2 bit
put o2 sensor in the drilled one
put drilled one in non drilled one
put non drilled one in o2 bung

Originally Posted by Ginseng

Buy 2 spark plug non foulers for 6$
Drill threw one with a 1/2 bit
put o2 sensor in the drilled one
put drilled one in non drilled one
put non drilled one in o2 bung

I did that right now with the bad cat I have. It hasn't set the P0420 yet but it's been thru like 5 drive cycles also and the monitor hasn't gone to ready. It will eventually, if you watch the back sensor with a scan tool it looks just about spot on.

I am thinking I have another issue...

Doing some basic maintenance, we changed all the fluids, and of course, oil, trans. and fuel filters.

The MAF sensor AND front O2 sensor are both a month old.

When we first got car, it kinda bucked on light throttle take off from a dead stop. Was getting MAF code....can't remember number though.

I bought aftermarket MAF and cleared code...all seemed good to go.

Few days later got the P0420 code, so just went ahead and swapped in a new Bosch O2 sensor.

Car RUNS GREAT, but keeps getting P0171 and P0420 codes after 4 or 5 drive cycles.

Fast forward to yesterday...

Bring home my scanner since it now has an ABS code.
I also do a live data scan and see front O2 is staying very low voltage at idle, like .120v or less, and rear O2 is staying right near the same....very little fluctuating, and DEFINITELY NOT any rapid, NORMAL O2 voltage movement...

I disabled MIL so it will pass emissions inspection (since it is due now).

But I am a little puzzled why it is idling so lean, and getting very little O2 sensor sweep????

Any ideas?? On what to check, or look for??

Only "MOD" under the hood (done by us) is an aftermarket intake tube and conical air filter.

Thanks.

p.s. I can post up the HPTuner file when I get home, but it's all stock tune, aside form slightly lower fan settings and now the P0171/P0420 codes disabling the MIL light. That's it. I noticed an HPTuners datalog shows high ST and LT fuel trims, as well as little to no fluctuation, so I assume that is from the lean O2 voltages? Just have no idea where to look for the ROOT problem....somehow it manages very good MPG's still...

Vacuum leak

Check all the vacuum "t's" around the LIM and base of the blower I had to replace them on my 99