wbw2

iTrader: (1)

hi guys, need 2 quick answers please......

1. what and where have you all found the best deal on an off road y for factory manifolds. FastToys has a MAC for 195, need to know if that is good.

2. since you are removing the catalytic converters(please bear with me), does this not increase the size of your exhaust, making air pull out of the combustion chamber quicker and maybe causing a lean/rich running engine? I understand that the O2 sims will make the engine run normally, but that is simply an O2 sensor problem that gets dealt with. even with the engine running normally, would the physical increase in exhaust size cause an un-tuned engine to run lean/rich? if so is there a simple solution or will I have to have it re-tuned after install?

1BADFNZ

Removing the cats will allow the engine to flow better. The LS1 has 4 O2 sensors, 2 on each side. The front O2 sensors tell your PCM the Air/Fuel ratio and it adjusts from that. the rear o2 sensors tell the pcm if the cats are working or not. Obviously if you remove the cats you need to put o2 sims in the rear.

shouldn't need a tune, if anything it'll make you run a tad rich.