Diablosport Forums

So I can't seem to get my truck to pass emissions due to the fact the catalyst and evap systems come up as not ready.

My truck is a 2004 that originally came with a 4.8L but now has a 6.0L. I also have aftermarket cats which I put on over a year ago. I haven't had any DTC's since I changend the cats so I don't think they are causing any problems.

I have completed the GM drive cycle many times as per the recommendation but I still won't pass.

Any suggestions would be greatly appreciated.

What is failing?

oh I have the same problem with my 99 Trans Am, I will try to scan the smog test (it only hooks up to the computer no sniffer here) can i send attachments on here or do I need you email?