Is there any way to bypass the factory smog pump system and EGR system on a 1999 4.3 4x4 auto tranny 4dr blazer? Thanks for any replies

 

Besides manually removing the systems, you would need to remove all of the codes from the PCM.

The air pump really serves little purpose. However, without some other modifications to the PCM, removing the EGR valve could create other problems.

Of course, removing either of these systems on an on-road vehicle is in violation of federal emissions laws regardless of whether you have emissions testing or not.

 

Why do you want to bypass both of these, are they throwing PCM codes?