Im almost finished with a 3.4 swap and have to modify my exhaust downpipe because my crossover flange is angled slighly towards the transmission. So by the time i bolt the downpipe on i cant get a cat to fit. My immediate problem is that I could build the exhaust for free if i could drive the truck the 40 miles there with just an exhaust to the end of the downpipe. I have driven the truck around the block a few times, just to get it up to temp quicker. It drives well but feels like there is no top end power. And is super loud. But i do not want to run the risk of messin up a lot of hard work.

 

Never mind. I got the chance to do more research and i think ill be ok. I have the 1st O2 sensor in place i dont think it would run that lean.

 

before it runs that lean it would run in limp mode.

 

I drove my truck around with open headers for 20 miles (to the exhaust shop)... it was fine, just super loud. o2 sensor was not hooked up, so it ran in open loop the whole time.