Aftermarket PCM

I keep seeing the aftermarket PCM tuners for the L67 PCM stating "not recommended for a totally stock Grand Prix. What is the reason for this? Will there be ill effects if I added it to a stock Grand Prix?

I have a 2001 GTP with a functional home-made cold air intake with high flow filter and I plan on getting a 2.5in ZZP downpipe with high flow cat as well (includes U-Bend delete)...will this go well with a PCM or is it not advised?

Thanks for the advice.

Just a disclaimer and a CYA but I see no issues running any of these re-programmed PCMs on a stock L67 GTP. I have the DHP v1.0 in a stock L67 Regal GS and even the fuel economy remained about the same. Plus L67 requires premium unleaded gas 91 octane or better so that is really not an issue. My GTP is moderately modded so it is a moot issue for me in that respect.



From DHP:

NOTE: This calibration was not originally tuned or intended for a stock Grand Prix GTP, but will work just fine without any other mods. However, we highly recommend adding a pulley and cold air intake before this PCM for the best possible results. It also works well with stock Grand Prix GTs. Premium fuel IS required.

If your looking for a tune for your PCM I would recommend contacting zzperformance. I have a stock GT and the tune made a big difference. Their website is zzperformance.com and they have the complete rundown of changes and price.

EP

If your looking for a tune for your PCM I would recommend contacting zzperformance. I have a stock GT and the tune made a big difference. Their website is zzperformance.com and they have the complete rundown of changes and price.

EP

Welcome to AF.

The OP asked a specific question which obviously you did not answer so stick to the topic of the thread. He did not ask where to get the re-programmed PCM. Most of our members that have contributed to this forum for any length of time know the typical vendors that supply them and the web sites which includes ZZP, Intense Racing, Xtreme Performance (3800performance.com), DHP and the W Body Store etc. Plus many of us have DHP and HP Powertuners for real DIY custom programming.

Also this is an L67 GTP so any info related to a L36 GT especially stock is irrelevant.

For the record I just ordered myself a PCM from Intense with the "normal" aftermarket PCM settings, plus "stock" shift points as they call it because I don't have a cam or high ratio rocker arms yet and the rear 02 codes deleted...I've heard the Magnaflow cat (which is coming on my ZZP 2.5" downpipe) has occasionally set off the rear 02 DTC's...so I figured I'll get it deleted before I get too into it.

It seems Intense has a 7 day return policy if I don't like the PCM, but overall I've heard good things about it...and apparently the owner is good to deal with so I can probably return it if I don't like it. Funny how 99.00 turns into 273.00 pretty quick when you add 2-20 dollar options, 100 core (which I'll be keeping the old PCM) and shipping...lol

I guess after winter next mods in line will be at least front PEM(s)...maybe a 72mm throttle body/spacer, AL104's and a 3.4 pulley...which should just about do it. I don't need to go too overboard as I plan to go to school in a year so I really should start saving, and I don't need a car that's more fast than reliable...at least with those mods it'll still be a good daily driver.

Some of us get the intermittent P0420 DTC with Magnaflow CATs or even other aftermarket CAT converters so getting the DTC delete makes sense versus spending $40 for a 02 simulator. I've been using an Intense PCM with customs settings in my GTP to include post CAT 02 sensor DTC delete for over 2 years now and no issues to date. I keep a spare PCM but it was originally a DHP but now with custom programming via a DHP Powertuner. Plus it passes annual state emissions inspection with no problems.