99 Ultimate Data Link Connector

Earthvillager

Ok, this is a weird one. I had what seems to be a common problem with a 99 Ultimate. The dash lights freaking out, drivers power seat not working and radio not shutting off after shut down. I cleaned all the engine and body grounds. The fix after pulling the cluster and tracing the harness I found the common thread was the Door module. I replaced it and it fixed all those problems. Now just prior to this, I tried to get it inspected and failed because the O2 sensor and catalytic convert gave a not ready signal. Ok, I know that disconnecting the battery resets the computer, So I drove hundred miles tried re-inspecting, still not ready. I know the O2 sensor and Cats are good by the performance and smell of the exhaust. Car purrs like a kitten. Afterward, I plugged in one of those Fixd scanners to DLC, which it could not find the sensor before the fix and failed inspection. It found the sensor and read just fine, all data showed up, no codes. I go to meet the wife for lunch to show her my handy work (her car). She calls as I'm driving with scanner live reading, finished the call and found I lost the signal to the sensor.So I rebooted my phone. Now the car does not find the sensor. (Coincidence or cause?) The Fixd sensor is good, I tested it on two other vehicles and read the data from both. retraced all connections under hood and dash all good. I suspect the ECM is not sending the signal to the DLC. which might be why the inspection scanner gives a Not Ready signal. I was wondering if anyone else had this issue and have a fix or thought on this one. thanks.

PF_Flyer

Not sure you can tell if the O2 sensor and Cats are good by smell and performance. I just had to replace a converter on one of my vehicles. Had a CEL throwing a P0420 code Catalyst System Efficiency Below Threshold (Bank 1), turned out to be the converter. But I had no unusual odors or change in performance at all