open loop

[sweet93z]

i have a 93 camaro with an LT4 hotcam. i got a tune from PCm forless... i ran my car on a scanner because it always smells like it is running so rich. i think it doing this because its stuck on open loop. the car was hot and should have switched to close. the scanner said that eveyrhting was ok. except the O2s were running really rich. moving from like 650 to 800. but never anyless. can anyone help me with why..? thanks

[smoknta]

In order for the car to go into closed loop, the O2's have to seen by the PCM cycling across 450mV. If yours never go below 450, it will never go into closed loop. Do you have long tubes, if so they may not be coming up to temp? You may have a O2 wiring issue also.

[sweet93z]

the car was sitting at 180 degrees. it had plenty of time to warm up. the wiring cant be messed up... its only 1 wire. and if it was there would be a service engine light. and the o2s are brand new because i thought it was maybe the O2s. so there is something wrong with the program or something.

[smoknta]

Just because there is one doesnt mean it cant be burnt, cut, or grounding out.
And more than likely the SES light would not come. I have had O2 issues in the past and have seen no lights and have thrown no codes.

[sweet93z]

this is not an o2 problems. They are reading fine. The car is stuck in OPEN LOOP. Since the car is running rich the o2s will read rich. WHY AM I STILL STUCK IN OPEN LOOP.

[harvickgm]

it is an O2 problem... do you have LT's and if so have you done the heated O2 conversion???

[sweet93z]

yea i have long tubes. i didnt do a heated 02 conversion. i have 1 wire running to my O2s right now. i have ran my car on this program before and my car would go into closed loop, the chip was also done from PCmforless before i got a cam. since i put the cam and got another tune it wont go now. that is why i dont think its my O2s because i havnent changed anything other than that.

[harvickgm]

its the O2's... look its been said over and over again.. this is the problem you are having. we all have had this problem, just because it worked before doesnt mean it will now. it worked fine when i had my auto in it but when i swapped to the M29, thats when i noticed it... do the conversion and get back with us...

[sweet93z]

ok thanks a lot ill try and do that.

[pcmforless]

hi,

if the car is staying in open loop it isn't being driven or the O2's aren't getting hot enough. You can try heated o2's as that usually fixes alot of these problems.

[sweet93z]

so the car has to be drivin to get a read. i let it sit but the car was at 200 degrees.

[smoknta]

That doesn't mean that the O2's are getting up to temp.

[Fastbird]

They'll most likely get up to temp while the car is being driven, but at idle....probably not. I was having the temp issue with my ASM headers.