I guess more never wracking than pain in the butt.

 

I just ordered a PCM from ZZ Performance as well, with the P0420 delete. I have a 2003 Monte Carlo LS with over 157k miles. I live in NC and my registration is due this month, which means I have to pass a state inspection first. Well, every since I replaced my catalytic converter last year, it has been giving me that code - P0420. The OE cat clogged up, which I believe was caused by a coolant leak from the intake gasket. I replaced all the gaskets and put on a Magnaflow high-flow cat, and at that time I had a Flowmaster deltaflow 40 series. Not long after that, I installed 2 Magnaflow straight-through design mufflers, one long resonator-shaped and a 14" or so oval in the back. Not sure exactly when it was, but sometime after that, the check engine came on. I bought a coder reader and every time I erase the codes, the catalyst monitor always throws the P0420 code when it completes. I've been banging my head against the wall trying to figure out how to fix it to pass inspection without redoing the whole exhaust. I really hope this new PCM does the trick and I can get it done before the end of the month.

 

You might just want to email ZZP and cancel that order.

You have the 3400 engine, and that PCM is for the 3800.

 

Am I the only old man with fuzzy vision that keeps thinking that "quick pcm help" looks like "quick **** help?"

Just had to drop in 2¢.

 

Here is a copy of the invoice from ZZP:

1xZZP 1.0 PCM
Year of your car:2003
Model:Monte Carlo LS 3.4L
Core charge:97-03 w/ prepaid return label
Option 1:none selected
Option 2:stock gearing
Option 3:stock injectors
Option 4:0420 code delete

 

good going man, i plan on getting my pcm after my dual exhaust then i want to get a downpipe, i just have to beat my brothers cobalt ss, sibling rivalry!!!!!

 

New ZZP PCM installed today. P0420 code is gone, but after driving a bit I got a P0135. Replaced upstream O2 sensor, then got P0134 and P0135. There was a little bit of stuttering and missing. Tomorrow I will inspect the O2 wiring harness and trace back the wires looking for shorts or kinks. I'm running out of time to get this car inspected by the end of the month. Any suggestions?

 

They started tuning the 3.4L?? wow

Good to know! haha