2004.5 - 2005 GM 6.6L LLY Duramax | Engine Tuning by PPEI

I had great service. Called multiple they gladly answered all my questions and was more then happy to talk to me to make sure everything was correct. Very polite as well. If you need tuning go to these guys they are the best.

05 lly

Contacted PPEI and what do I have to say. And amazing company and guys to do business with. Fast easy and nothing but a positive attitude from everyone. All I know is my lly runs great and doesn't smoke. Thanks PPEI for all that you do. Dannie

2005 LLY

I have a basically bone stock LLY and after coming from a newer 6.7 Cummins was underwhelmed by the towing performance and lack of exhaust brake function. The team at PPEI was super helpful and set me up with a dsp5 switch and tunes as well as an autocal. They even enabled the exhaust brake function in both tow tunes per my request. After the tuning process failed using the Autocal, they offered to bench tune the ECM and did so with incredible speed in turnaround. Got my ECM back and installed and the truck runs amazing now. Throttle seems smoother, truck runs much better and I’m looking forward to the first tow to test out the exhaust brake function. 100% would recommend PPEI!