well here's my case....over the winter i ripped the motor and drivetrain all out and rebuilt and built up everything from the front to the back....now i got it all back in, and the motor is just about to be ready to fire up...the thing is tho, all i have is open long tube headers on the car right now. Today i went and talked to the guy doing my exhaust, and he said since i'm putting duals on my car, he wants to put an X pipe in there also, but the thing is he is gonna put some pipes on there, paint them, then cut them where they burn off and thats where he is gonna put the x pipe...so that means he has to start the car up. And I haven't started the car up at all after the new cam, new bearings, and everything else was redone in the shortblock. So everything still needs to be broken in...and the reason i haven't started it up yet was because i wanted to put exhaust on it for when I fired it up incase there was a problem with the engine, i would be able to hear it. so if it knocked or pinged i would be able to hear it instead of the exhaust drowning it out...also i got a heated o2 sensor, and i was going to put it in the s pipe right after the header, and that pipe is not in yet, so that would mean i would need to start it up without the o2 sensor and it would run like ****....i'm just kinda loooking for some insight on what to do. I dont' want to start it up with no exhaust, but it sounds like i'm gonna have to...is there a way i could quite it down so i could hear the engine during break in, instead of the exhaust...and also what should i do with my o2 sensor????

 

any1??

 

You can start the car without the 02. Your car will be in closed loop and doesn't take any imputs from the 02 until it goes into closed loop. Have you done any chip work? You can program a chip to keep the car in open loop as well. You may want to check but I believe most people break in engines with exhaust manifolds before they run a new motor with headers.

 

yes i got a chip burnt by pcmforless, so its tuned for my mods...i don't have stock manifolds, all i have is the headers...because i bought it with crappy shorties, i ripped them off and got some long tubes now...so your saying i don't need an o2 sensor to start it up? is there some how to quite it down with open headers without putting a full exhaust on?? i just dont' wanna show up at the exhaust shop, have the guy put some pipes on, then start it up and it won't start or something..ya know??

 

There is no way to quiet open headers. Your car will run in open loop for a bit but then will take readings from the 02 when it goes into closed loop. You would have to act fast. On a side note I would still look into doing chip work yourself. Mail order tunes are a stab in the dark no matter what you told them your mods were. If you get your car to an exhaust shop chances are it will run when they are done with it. Adding a few exahust components won't make your car suseptible to not working.

 

I thought the car wouldn't try to go into closed loop until it saw O2 crossings.