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I had issues with TunerPro RT on my 1992 Corvette until -=Jeff=- provided a properly modified adx file. In the meantime I decided it would be good to have a Snap-On MT2500. According to both my car never goes into closed loop and the left O2 sensor bounces around. The odd thing is that the car runs relatively well. I also just got an ABS and ASR fault in the DIC whlle the car was idling. The readings show LF wheel at 21 MPH while sitting still, but I have never had these issues before. I will see if they faults clear when I take the car for a drive next time.
Showing open loop even though I waited until fans came on.
Wow, 21 MPH, on only one wheel.
Not sure about these errors as the car runs pretty well.
Typically a vehicle goes into Closed Loop when the O2 sensor starts sending information to the ECM and the coolant has warmed up. It would seem that one of these conditions has not been meet.
Typically a vehicle goes into Closed Loop when the O2 sensor is starts sending information to the ECM and the coolant has warmed up. It would seem that one of these conditions has not been meet.
I didn't capture a photo, but the MT2500 and TunerPro RT both showed the voltage for the left O2 sensor jumping around a lot. Looks like it's time to replace the front O2 sensors. The engine coolant temperature was well above what should be needed for closed loop, it got into the 200s.
Last edited by JimLentz; 10-26-2016 at 07:41 AM.
Reason: Added info
If your car is an LT5 it has heated O2 sensors which help the O2 sensors get hot enough to start sending data and making the car go into Closed loop. The heated O2 sensors are protected by a fuse...not sure which one (owners manual??) but before you replace any parts take a close look to see if the fuse is OK.
Last edited by gmboileau; 10-27-2016 at 12:28 PM.
Reason: Clarification
Your car has heated O2 sensors which help the O2 sensors get hot enough to start sending data and making the car go into Closed loop. The heated O2 sensors are protected by a fuse...not sure which one (owners manual??) but before you replace any parts take a close look to see if the fuse is OK.
Aren't the rear (downstream) sensors the ones that are heated? I thought the front (upstream) O2 sensors are the ones that impact closed loop operation.
Aren't the rear (downstream) sensors the ones that are heated? I thought the front (upstream) O2 sensors are the ones that impact closed loop operation.
You didn't/haven't mentioned LT1 or LT5 in this thread. Which?
You mention -=Jeff=- so maybe an LT5?
A '92 I don't believe has "post cat" O2 and unless you've added the heated O2 in the pre-cat I believe they're both single wire and NON-HEATED for LT1, LT5 - heated, LT1 - single wire I believe.
You didn't/haven't mentioned LT1 or LT5 in this thread. Which?
You mention -=Jeff=- so maybe an LT5?
A '92 I don't believe has "post cat" O2 and unless you've added the heated O2 in the pre-cat I believe they're both single wire and NON-HEATED for LT1, LT5 - heated, LT1 - single wire I believe.
I changed the left O2 sensor, the fuel filter and the trans fluid in the ZF6. Now the mV reading for both O2 sensors jump around according to TunerPro RT, is that normal?
If an o2 reading stays at the same number for a while, it's a dead o2. In closed loop, the numbers should go back and forth quickly.
Thanks, that is what TunerPro RT is showing. I had problems getting the Snap On to talk to the ECM, but it gave me ABS options. I like that the MT2500 directly shows if it is in open loop. I may have changed the driver's side o2 sensor without needing it. It wasn't bad after I finally broke it loose. I bought 2 sensors, but couldn't figure out a way to get the passenger side one off.
10-25-2016, 07:18 PM
TunerPro RT and Sanp On MT2500
For 1992 heated O2 sensors are on LT5....LT1 single wire.