'96 Caprice 9C1 LT1 EGR removal...

[DSM-Mark]

Hey guys,

My old man just bought a '96 Caprice Ex-cop car with the LT1 for his street rod project, which currently sports a carburated 350. Problem is, the exhaust manifolds on the LT1 which have an EGR off-line will not fit in his car. So he plans to replace those headers with his current headers, which do not have an EGR off-line. So, he's somewhat planning on removing the EGR system completely with block-off plates. I've heard that this will trip EGR codes in the computer (not surprising) and indicate the check engine light periodically. Question is, will it affect the car's driving at all? Will it put the computer in safe mode? If it does, how do you get around this problem? Thanks!

LT1-Mark

[ziffdine]

Carbureted 350? Doesn't sound stock. 1996 9C1s with LT1s were fuel injected, as were all cars after about 1991. You might want to check that.

[DSM-Mark]

Originally Posted by ziffdine

Carbureted 350? Doesn't sound stock. 1996 9C1s with LT1s were fuel injected, as were all cars after about 1991. You might want to check that.

Sorry, I think you read something wrong

The Caprice has a fuel injected LT1. The engine currently in the street rod is a carburated 350 with no EGR system. We want to reuse the exhaust headers from the carburated 350 on the fuel injected LT1, but the fuel injected LT1 expects an EGR signal, and with the headers we want to use, there can be no EGR system, so there would be no signal!

[redimpss5]

the car will run like crap if you take off the egr!! the only way you can smooth it out, is with the LT$ cam! this engine will run so good with the smog stuff, you wont believe.

[RABarrett]

Though the engine will run like crap, the computer will seek an EGR signal, and go into failsafe when a code sets. The system will test the EGR on coast down, looking for the EGR to affect the Map readings. If it does not see one, the result will be a mode limiting timing advance and mixture control. Some food for thought. Ray

[RABarrett]

Though the engine will not run like crap, the computer will seek an EGR signal, and go into failsafe when a code sets. The system will test the EGR on coast down, looking for the EGR to affect the Map readings. If it does not see one, the result will be a mode limiting timing advance and mixture control. Some food for thought. Ray

[3859C1]

I have disconnected the EGR sensor and blocked any vacuum lines to it. I have also deleted my A.I.R. and smog pump. I have replaced the factory exhaust manifolds with non A.I.R. headers that accomadate the O2 sensor. I also have true 2 1/2" dual exhaust with flowmaster 2 chamber mufflers. My motor is quite different though being a 1988 9C1 with a 350 Q-jet feedback engine. It is computer controlled and has alot of the same sensors (smog wise) as the later LT1's. My car seems to run pretty good but I am wondering if it could run better if I hooked my EGR back up. Did deleting these smog components have an effect on performance positive or negative? My ECM is much simpler than that of the LT1. Is it less sensitive to modification? Can I delete my knock sensor or desensitize it? I am worried that it is mistaking my loud exhaust is for spark knock.