Open loop for 'insufficient temperature' at 190 degrees. How?

[stomper]

I have a 2000 4.8 in my 73 P10. I'm chasing some codes which are probably related to the oxygen sensors. However first order of business was putting in a thermostat where there wasn't one before. I still get an open loop error because of insufficient temperature which I was assumed because I rarely got over a hundred and sixty degrees with no thermostat in there. Now it's coming up to temperature but still won't go into closed loop. Prior to putting in a thermostat it would occasionally go into closed loop but ran like crap probably because of the oxygen sensors and then it would go back into open loop because of system failure. Any ideas on the temperature issue?

[davepl]

What the open loop temp cutoff set to in the tune, can you tell (ie: get into the tune)?

If I were you and you were me, you'd try a stock thermostat for a 2000 4.8L because they might operate at 205F and not go into closed loop till 200 or something!

[stomper]

The highest temp thermostat ORiellys had was 187 and that's what I put in. I don't have a way to read the setting for closed loop. It should be factory unless the guy that deleted VATS changed it. It has gone into closed loop occasionally at 160 or so. How many temp sensors are there on my LS? Could there be one that I'm reading on Turbo Pro and another that engages closed loop?

[stomper]

I guess I'll get a couple new O2 sensors and hope for the best.

[truckdude239]

Normally it wont go into closed loop till the o2 sensors are warmed up tbey why they put heaters in tbe sensors i read 02 sensors normall heat up fro. 600 to 1200 degree depending on the sensor but i will not go jnto closed loop untill the o2s are up to temp

[stomper]

I drove it all day today and it went into closed loop quite a bit. Totally ran like crap. -30%+ trim on bank 1. I assume due to the failed o2 sensor. Then went back into open. I'm confident new o2 sensors will fix this. I have them on order.

[stomper]

Update:

Got the new O2's in and it runs great. Maybe after cycling up to 190 a few times it goes into closed loop easier? My phone is dead so I can't confirm the new sensor operation with Turbo Pro app but the exhaust doesn't smell rich anymore (from open loop) and it always runs smooth.

[Jstock85]

What brand sensors did you go with?

[stomper]

Originally Posted by Jstock85

What brand sensors did you go with?

Denso. Just from a little reading I did pointed to that as a decent brand. First one's I've ever bought.

This swap is a bit of a cluster. The proper sensors I just bought for the donor application did not have matching ends. Upstream, downstream, or Canadian manufacture, none worked. So, I had to snip off the new connectors and splice the old connectors on the new sensors. It appears to be a harness for a newer 6.0 truck but who knows. Everyday I find something missing, wrong, broken, hacked, odd, or a faster falls out.

[stomper]

Originally Posted by davepl

What the open loop temp cutoff set to in the tune, can you tell (ie: get into the tune)?

If I were you and you were me, you'd try a stock thermostat for a 2000 4.8L because they might operate at 205F and not go into closed loop till 200 or something!

Wow! Dave! Noticed your sig then just read about your Pontics on Hemmings. Super cool.

[Jstock85]

Same here man! been a hangup or screwup on every corner. Been nickel and dimed to death. This is my first rodeo and I've enjoyed figuring everything out. Maybe it'll be smoother next go around.

[davepl]

Originally Posted by stomper

Wow! Dave! Noticed your sig then just read about your Pontics on Hemmings. Super cool.

Thanks! BTW, if you want to send me the tune file, I can check what the open loop cutoff temp is. I can't CHANGE it without buying a license for that file, but I can read it, if that helps.

[stomper]

Originally Posted by davepl

Thanks! BTW, if you want to send me the tune file, I can check what the open loop cutoff temp is. I can't CHANGE it without buying a license for that file, but I can read it, if that helps.

Thanks Dave. I'm not sure how to get the tune out of there yet. I have an old cable to connect the ODB port to my laptop but I need an adapter to connect to the USB. It's from the 94 Impala days. I was mailing 3.5" floppy discs with tunes back then! I should just find a tuner in my area and run my truck in there.