Anyone have any problems with IM 240 ready flags? I got car in the shop the other day that a so called local tuner worked on. The car is a 01 LS1 C5 with a Vortec blower at 6 PSI. LMG long tube headers were installed, he removed the CATs and get this. He moved the rear O2 sensors to the front position and installed sims in the rear positions.

I got the car because it would not pass emissions inspection here. It was setting codes P1133 and P1153 if I remember right these were for the front sensors for slow or limited switching. It was also throwing codes for the rear O2 heater circuits. Not to mention that when the guy installed the headers he failed to use the supplied clamps so there were numerous leaks causing sensor dilution. I found the heater circuit problem was due to one of the sims being cooked by header heat.

I reinstalled the CATs and all the sensors, recalibrated the PCM because it was showing up to +7% correction at steady state cruise conditions. I ran the car for the required IM240 tests on my chassis dyno but I could not get the PCM to give me a ready flag on any of the tests. No DTCs were recorded by the PCM. The GM specs did say that the EVAP and AIR systems may not pass due to ambient humidity and temperature conditions. The only flag I got to clear was the heater circuits. Now the car would easily pass sniffer tests with the new CATs, and it smells soooo much better

Anyone got any ideas. I spoke with my GM Powertrain contact and he says everything should pass. Here in Oregon we have to have the IM 240 systems all pass the ready state, no ready means no registration tags.