So, I need to have my newly purchased 96 Z28 pass emissions here in CT within 30 days, or else I'll be hit with a late fee, and will be unable to renew my registration when it comes due again.

I have a stubborn P0400 code (EGR malfunction) that I haven't been able to diagnose and fix yet. Here in CT (as in a total of 21 states, I believe), cars 1996 and newer are "plug and play" tested via the OBD port - no tailpipe test. With the SES light on, it's an automatic emissions fail.

I just got off the phone with the emissions department at the CT DMV. I asked them how many status monitors can be in "not ready" status and still pass the emissions test. When I told him the car is a 1996, he said that the catalyst monitor must be ready, but I am allowed 1 other monitor to be "not ready." I used my OBD2 scanner tool to clear the P0400 code, and have driven the car enough such that 7 of the 8 status monitors are now set to "OK" with no codes showing. The EGR monitor is "not ready," but it has yet to store a trouble code (assuming it will be P0400 again) in pending status. So, according to what the DMV told me, my car will pass the emissions test as it is... 7 of 8 monitors in ready status, with no trouble codes present.

Seems that this is a loophole in the system which will allow a car to cirumvent the testing process... Just curious if anyone else has experienced this before? I'll find out for sure tomorrow morning when I actually take the car to have it tested, but I am very hopeful at this point.

 

This worked out pretty well. I cleared the code, and all 8 monitors showed as OK after I drove the car for a while. Then, the SES light came back on with the P0400 code. Cleared the code again, and waited for all 8 status monitors to show as OK. Took my Camaro to get tested, and it passed. On the way home from the testing center, the SES comes back on again, with the P0400 code. Glad I invested in an OBDII scanner! Now, just need to figure out what's causing the car to throw the P0400 code - car drives perfectly though.....

 

Probably insufficent flow issue. Things can get a little carboned up. Remove and clean it, reinstall and see if that doesnt attend to the problem.

 

most oem gaskets have a metal screen in the gasket on the egr to prevent it from becomming carbon fouled. typicly, they clog up and it stops working. pull it off and check it out. i had that issue on my dd, a 95 blazer. well, even that didnt fix it. when i came time to do the head gaskets, the entire head was plugged up with carbon. but pull it off first and see what the issue is. might just need a new egr valve