BigBoi4Lyph

so last time i ran live data on my iroc i noticed that if i get my iroc idle within about 1 min my 02 would read 0mv.

im wondering if its because i dont have a heater o2 and im running shortie hooker headers?

like the o2 is cooling off at idle maybe?

possibly my rought idle(well slightly rough)

heated o2 possibly the answer?

thanks

3.8TransAM

Heated 02's should fix that for you.

Even stock manifolds will do it on a colder day if u idle for awhile.

When u go to headers, whether shorties or long tube, it just gets worse and happens far far faster

I believe the number of the 02 u want is a Delco AFS-74. I run one in my Formula for the same reason.

BigBoi4Lyph

thanks alot!

but would it going to 0mv cause it to run rougher at idle?

and even my performance off idle like idle to WOT?

Kevin91Z

iTrader: (1)

Yes because the computer thinks the engine is dead lean ( 0mv ) and is adding a ton of fuel to get the O2 to come back to normal.

You might also have a gasket leak on the driver's side header that is allowing extra air to enter and affect the O2 sensor.

BigBoi4Lyph

yes it does seem to run richer at idle you can smell the exhaust more then you probably should be able too.

and exhaust leeks probably not i have retightened all the bolts and listened to the header connection points with thats doctors thing.(vacuum tubes with ear buds) haha

with no exhaust leaks.

but either way when i do the heated o2 i have to pull the headers to get a new exahust bun welded on as mine is missing half the threads and is sealed but wouldnt seal again if my life depended on it. so i will have new gaskets going on aswell.

thanks again!