OK, I was coming home from work one day and stopped by the post office to gather my mail. I left her running, and as I came out, I saw she was shuddering. "Oh no", I thought, and jumped in. She was running at around 1500 RPM's, and shaking like a leaf. Then she revved up to around 3000 RPM's, held it for a second, set a trouble light, and settled down somewhat. I drove her home, grabbed my scanner, and it said the o2 sensor voltage was too high. I checked and the rear sensor wire was broken. I bought a new sensor, installed it, and then it complained about 02 sensor malfunction and a bad cat. I grabbed a used sensor I had lying around, installed it, no trouble light. So, I bought a high flow cat and a sensor simulator, as well as a new front sensor. Now still no trouble light, but the scanner says my "HO2" sensor is not emmisions ready.... I have to get inspected this month. Help??

 

Do they hook up a scanner, like you did, if there is no CEL on?

Most states, I thought, don't care unless there is a CEL.

 

the only state you have to fear is California, you should be set anywhere else.

 

You could always do the sparkplug non-fowler trick with the rear 02. Take the sim out and install a real sensor in a couple of sparkplug non-fowlers.

 

i have had a simulator in my truck since '07, it hasnt worked since day one, lol. give me the P code and ill see if i can get the DTC sheets so you can diagnose it.

 

In North Carolina, they plug you into a computer and wire your stats to Raleigh's computers. I don't know if they'll pass it anyway, though. Another thing is I want it running efficiently; that's a main reason I'm concerned. BTW, which one is the "HO2" sensor, front or rear? The one my scanner refers to as the O2 sensor is proclaimed ready.

 

Thanks, but it's not throwing a code, the CEL is unlit, and the truck is actually running rather well, which is the puzzling thing. I just checked the emissions readiness test on my scanner and it simply says "HO2 Sensor: NOT READY." The sim is through Fastman, and I've heard good things about him.

 

did you check the system when it was in "closed loop"? if it was in open loop, it wont read the O2, it uses a different system.

 

That'd be my guess as well, Helms. The H02 (Heated O2) sensor needs to warm up to a couple hundred degrees before it sends info to the PCM. Thats one of the reasons why they have open loop mode and closed loop mode.

Next time you drive it for a couple miles, to a grocery store or wherever, park it when you get gome (but don't shut it off) and plug the scanner in again, see what it says.

 

Thanks, y'all, but this is still acting up. I had to pull my battery and install it in a backhoe, so I thought that may be it; that it had to run 50 - 100 miles before everything settled in. I have since put over 300 miles on her, and still the same thing. Any other ideas??