I've done a search, and looked at many of the pages out there, but was wondering if there are any that cover TunerCat? I have 2 Z28's and I don't want to get Lt1Edit because I could only program one Vin, right?

Is there an easy way to tell if the program you pull from the ECM has been tweaked by anybody? In particular my A4 shifts really screwy, and I really think someone threw an HPP on it or something (before I owned the car). I'd actually prefer to get that back to a stock shifting program as my Fiancee drives it, and I'm trying to get as many miles out of it as possible.

My other question is I have the M6 Z28 below, which has been tuned for no EGR, no AIR, and no CAT. I now have to bolt all of the crap back on, so what kinds of things will I need to change? I see with Tunercat, there is the option to ignore the error's set because of the EGR and AIR, do I just re-enable it there? Once I bolt the parts on, I will need to activate them in order for them to work right? (With the exception of the Cat)

The A4 has lately been getting worse gas mileage, it seems that as the miles go on, it gets worse gas mileage. I know that you can expect some of that, but going from ~20-22 to ~16? Something's wrong here. Last october, I ended up throwing a lot of parts at the car because it was running like crap. Now I got the "running like crap" sorted out but still am puzzled why the gas mileage is so bad?

I replaced the spark plugs, the wires, and the coil. The fuel filter has about 20,000 miles on it. The fuel pressure at idle is 36psi. Fuel pump replaced 30k miles ago. Fuel pump relat, fuel pressure regulator replaced also 30k miles ago. The old spark plugs were fine, but the gap was a little excessive. Now when I look at the datamaster readings, it is usually around 118 instead of 128. I still cannot figure out, could this be caused from:

1. Leak in exhaust system
2. Air leak after the maf
3. Map not reading correctly, or bad seal around it?
4. Bad or leaking fuel injectors
5. Opti, rotor?
6. Slow o2 sensors?

Is there a way to tell by looking at the datamaster logs, which of these could be a possibility? For what it's worth the car has 155,000 miles and has never been rebuilt, and I have never replaced the 02's in the 30k miles I have owned it.

Thanks and sorry for all the questions

 

You could have lazy O2 sensors causing your problem. Check the other things you mentioned as they to would have a effect on it. And as for enabling the emission controls, yes you can go back into Tunercat and enable the diagnostics.

As for knowing if the PCM has been messed with, well you can do a PCM read on the PCM you have now and compare it with a known good virgin PCM file. Thats about the only way I can think of to know for sure. If you supply me with your VIN for the car I can give you a fresh GM Calibration to compare it with.