My mail ordered tune from solomon is on its way back! I have a few concerns though after reading his email. I checked to have all AIR/EGR/EVAP all removed/tuned out of the PCM. I didn't plan on removing the hardware from under the hood anytime soon though. Will this cause trouble with engine performance? I have a plug for the CAI to the AIR pump, but I was thinking the AIR pump is closed when its not operational so it wont cause exhaust leaks. Will the turned off EGR valve be an issue? I'm not sure it was working correctly before anyways.

Thanks

 

What exactly did he say in his email? Did he not turn them off? Or did he tell you to make changes to the hardware?

The systems need to be turned off in the tune, or you will get SES lights and codes, an it will affect the way the engine runs, negatively . OBD-2 has multiple checks on those systems. In turning them off, it also needs to be done in a way that a "system not ready" flag does not appear when an emissions test is connected to the ALDL connector under the dash. Different jurisdictions have different rules as to how many "not ready" flags they will allow without failing the test.

You can leave the hardware there with minor tweeks, as long as it is in good shape. The AIR system has a check valve in each exhaust manifold connection. As long as those valves are working, they prevent exhaust from backing up into the AIR plumbing. But those valves do carbon up and can leak. There is also in integral solenoid operated stop valve internal to the pump. It gets a bit more complicated because there was some hardware added as part of the recall on the 95-97 AIR systems.

The EGR valve pintle blocks flow of exhaust gases into the intake manifold, as long as there is no vacuum to the diaphragm on the valve. If the EGR is stuck open, or if the EGR vacuum solenoid it leaking, there will be exhaust gases leaking into the intake manifold all the time. I would take the vacuum lone off the EGR valve and plug the end of the vacuum line. To make sure the EGR valve is sealing to the manifold, reach back and push the diaphragm to open the valve. Engine should stumble, may even stall. That indicates the pintle is sealing when the valve is closed.

EVAP is a mixed bag. If the system is not purging the charcoal canister, where is excess fuel vapor going to go? Or, if the EVAP purge solenoid is leaking, there will always be purge flow into the throttle body. To prevent issues with the vapor building pressure in the tank, I would (and have) pulled the vent hose off the canister, and put a fabric sock over the end of the hose. You might notice an increase in fuel smell near the left rear fender. I would also cap the connection on the throttle body to prevent a vacuum leak in the event the purge solenoid leaks.

 

Yea all of the systems are tuned out and he recommended removing the hardware. It appears that it will be okay with the hardware intact, at least if the EGR valve is sealing and there's no leaks in the AIR system.