URD O2 Simulator

I don't recall the exact part number but I had to learn the lesson the hard way. I'll look into that link you sent and see if I can check the ECM.

A bit of history for everyone:

Replaced the 3.4 with one from a 97 4runner and used my existing wiring harness and everything hooked up fine. The previous engine broke the top of one of the pistons by the ring groove and had skipped a few notches on the T-belt. Truck still ran remarkably well but for economic purposes it was easier to just R&R the engine. Went off without a hitch. Needless to say the CEL was on with the old engine but it had a lot of issues so it was understandable.

Got the new engine in and all seemed well. Then........

CEL came on saying bank 1 sensor 1 heater circuit. Guy at Advance Auto said it meant bad upstream O2 sensor. Keep in mind the truck ran great, no apparent issues. So I bought a new BOSCH universal sensor and the truck could barely pull itself out of the driveway. Took that one back and got a BOSCH plug n play sensor. Still couldn't pull itself. Got some advice from the crowd here and bought a DENSO plug n play. Truck peels out again but the light is still on.

SO.....I chatted with another guy at the parts store and he was stumped and said maybe my cat was bad due to excessive oil buring of the old engine and to hollow it out. So I went home and took it off only to find that someone beat me to it. It was already hollowed out.

That's when I started doing some research and discovered URD and the O2 sim. It says that if you are running a cat free system or straight pipe and have a CEL, this would correct that (of course I only race my truck and would never drive it on the street...nudge nudge). So naturally, I assumed this was the next direction for me to follow. Tried that and that's when I started this thread.

So to sum it up, the truck runs like a bat outta hell with no performance issues at all, great MPG, awesome acceleration, no issues at all other than a chronic CEL. But I'm the kind of guy who laughs at folks when I pass them and their CEL is blazing on their dashboard so I really want this thing to go OUT! Not to mention, I might see some MPG gains if it does.

PSU...that link didn't show anything for the scanner. I'm intrigued because if you've gotten that much use out of it, I'm sure I will too as many people come to me with vehicle issues so I know it will be money well spent.

There ya have it folks.....that's the story

 

98tacoma,
Upon looking at the link you sent, it does make some sense until I look at the hints. Then I get confused becaue it says...

HINT:​

​

​

​

​

Connect terminal HT1 to bank 1 sensor 1.​

Connect terminal HT2 or HTS to bank 1 sensor 2

Where would I connect HT1 to bank 1 sensor 1? Or am I overthinking it?

Then assuming I can figure that out and I have proper voltage, then I replace the ECM? Oh my...now we're talking big money. Maybe that light isn't so bad afterall.

BTW....where do you get these links? I 'd be interested to see what page SF-55 has to say about checking the resistance of the sensor.

Have you ever done this procedure before? It sounds fairly straight forward.

Thanks again guys

 

I only have 1 cat and yeah, it's definately hollow. Looks to have been that way for some time since I had to grind the bolts off to get it off. There was no way a wrench would bite.

 

So I don't have a bank 2 sensor?

I have an upstream sensor and a downstream sensor. I thought one was Bank 1 and the other Bank 2. Have I been thinking wrong the entire time?

 

Ahhh.....makes total sense. Thanks for the clarification.

Now.....if only this CEL was as easy to solve.

 

No, I haven't done anything like that. I don't think I would even know where to begin.

I'm not so good at measureing ohms on my multitester. Continuity...no problem. Voltage....no problem. Ohms.....problem (mainly because I don't know what to set the tester on or know what I'm looking for).

 

So essentially get on my back under the truck, unplug the sensor and test it? But there are 4 wires I believe, maybe 3, I can't remember. Regardless, how do I know which are the heater wires?

On the sensor that is, not the harness from the truck. Right?

This is uncharted territory for me. I can manage mechanical stuff with my eyes closed but when it comes to this kind of stuff, I'm a real dummy. But also a quick study.

 

Very useful link there. Thanks much.

Am I supposed to test that mo fo at operating temp too? 1,472 degrees? WTF?

I'll check for a damaged harness too. Didn't really cross my mind until recently. Won't be able to do much of this until next week since it's a holiday weekend and the lake is calling my name.

 

This is great advice...I totally skipped right over the engine swap talk.

Fink

 

Now, you know your not really mechanicing unless you get burned or cut, then continue to bump your wound on something every time you work on the truck. Or, you get oil in the burn or cut. Either one.

Other advice: You should have went ahead with the lift kit so it's much easier climbing under the truck.

 

So Gadget finally replied to me and pretty much told me that the URD sim wouldn't solve my problem. I pretty much assumed that at this point. Looks like I spent 106.00 for nothing. Oh well, it's only money.....right?

I did find it a bit tricky to get much dialoge out of him, I'm sure he's busy fielding emails and filling orders so I can't be too upset about it. But the one thing I wanted to know was that if I'm getting a 135 error code only and I don't have a cat, then would I even need the URD sim? It sounded to me like if I can trace the issue to a bad harness, cut wire or bad ECU my CEL would turn off. Thus making the URD sim worthless to me.

Or....once I get the 135 code resolved, would I get a different code due to the lack of Cat and indeed need the URD sim?

Does that make sense?

BTW....still haven't had the chance to check the wiring harness. Home remodeling and a pregnant girlfriend seem to be the main focus lately.