Check Engine light

Wow. You'd think that out of the three components in that system (the computer, the harness, and the sensor) the one that sits in a 1300?F exhaust stream all day would be the most likely culprit. Has the system actually been diagnosed?

For the record, I've replaced one computer for this problem, no harnesses, and about 1000 AF sensors.

Buying a cheap code reader will do nothing for you here. You already know what the code is. You need someone with a scan tool that can access the entire data list and actively test systems (those are over $2000) AND that someone needs to know how to interpret what they are looking at. If I were you I would ask to have a sit down with the service manager of the dealer that recommended replacing the harness and ask for a detailed explanation as to why the technician is diagnosing this extremely rare case in your Toyota. I'm not saying the harness isn't at fault, it only that factory wiring problems are VERY few and far between. VERY.

True, not that ECM and harness can't go wrong. But it may be the Denso oxygen sensors acting up. I'd buy Bosch sensors, best in class.

Wow. You'd think that out of the three components in that system (the

It sounds like the dealer is a crook, harnesess last the life of the car. Contact toyota to complain and go to another dealer, Could something like your o2 sensor be bad.

Thanks for all your responses....

I already went to the dealer and he has diagnosed the whole problem using the scan tool (same goes for my mechanic). The dealer also gave me in writing that they suspect harness is an issue and if that does not solve the problem of CEL "only the" will they replace the computer.....

Also....... I had my sensor changed and I bought the expensive one............not the cheap one.....

I guess my Q to you guys is can I pass inspection test if I erase the codes just before inspection using a cheap scan tool......?

Today i used OBD-2 and erased the code and my car passed NJ emissions test. U can try too.

Pull the ECM fuse for a couple of minutes (in the engine compartment, driver side fuse box). This will clear the codes. However, if your oxygen sensor is bad, you probably won't pass (this is a good, inexpensive test, as many centers retest for free!!!).

If it's the oxygen sensor, you should be fine now that you replaced it. For one I don't care much for Denso sensors. They make excellent alternators but their oxygen sensors are crap. I use Bosch sensors, best in class:

BTW, P1133 is insufficient sensor switching; P1135 is oxygen sensor heater circuit problem. How did that dealer arrive at ECM problem and harness. Wanting to charge you for the harness and then the ECM. You'll pay more than your car's worth after all the work.

snipped-for-privacy@gmail.com wrote:

Also, regarding the Autozone OBD-II reader. Can't you borrow it for free to check the codes and clear the MIL light? Many of us do.

snipped-for-privacy@gmail.com wrote:

That won't work, and here's why:

In your engine computer are a list of "monitors". These monitors are programs that run during specific periods of operation to determine if your cars systems are working correctly. There is an EGR monitor, O2 monitor, catalytic monitor, misfire monitor, etc... These monitors are read as pass/fail/incomplete by the OBDII emissions software. In order to pass, you have to have a certain # of complete monitors, with no failures. So, if you have the required # of passing monitors and 1 failed monitor (your check engine light), you will not pass emissions. When you go to clear the check engine light, all of your monitors will reset. Now you will not have the required # of completed monitors, and again you will not pass the emissions test.

They want in your pocket before they get into Toyota's, huh?

Anything is possible, I guess, but I tend to doubt the veracity of most dealers, and especially those that come up with this sort of crap.