Hello, I have a problem with my 92 4runner 4x4 3.0l v6. Gas mileage totally stinks first off. Seems worse when check engine light is on. I have reset the ecu(by pulling fuse out for 10 sec)and dissconected the battery several times to try and reset the system. Ok so I take the truck to the shop and they plug into it and tell me its an ecu code. They tell me we can replace a $40 part for $200 and that may not even be your problem. So I replace the part he say's might be the problem. which was not the problem. I replaced the ecu modulator, took me about $40 and 5 minutwes to replace and the shop wanted $200. So my question is.. Does anyone here know what my problem may be? Or whats next in line to replace. I know the 02 sensors are expensive and don't want to buy them unless I really have to, maybe the ecu valve? any suggestions? Any help would be greatly appricated. Thank you.

 

what code did you get

 

I didn't get a number or anything. He just said it was a code for the ecu. Should I take it to another mechnic for a second opinion and the code? Also it won't pass emmissions. I replaced the plugs and put new distributer rotor and cap on it. It seems too run fine just the check engine light is on, and I thinks it causing more fuel consumption.

 

if you have a autozone or something they will pull the code for free

 

oh sweet. I'll reset it and drive it up there as soon as the light comes on and let you guy's know the code. Maybe you can help me save some $.

 

Sounds like something I've seen lately...CEL, but no code. Re-set is good for about 50 miles and then the CEL comes back. So, as I also happen to have had a small exhaust leak and (important part here) a spare piece of exhuast pipe WITH a new 02 sensor, I installed the pipe WITH the new )2 sensor. No more CEL!

Short the terminals, check the code, and then look up the results. Let us know how it goes...

 

I beleive it is CEL, and i did have a slight exhaust leak but, I tightened the bolts and leak is gone, do you think lower 02 may be bad? And thats what its doing^ after I reset the ecu, I drive about 50mi then the light comes back on. Mechanic was fairly certain it's not ecu valve. Any suggestions? Thank you.

 

Well, for me it was simple - replace the 02 sensor. But I just happened to have a spare on laying around, so it's not like I had to go out and spend $100 on the CHANCE that it was the sensor. Just a lucky shot in the dark.
As for 'lower' 02 sensor, I think the 3.0 has only one sensor, just in from of the cat. It's easy to replace, two bolts off, pop off the sensor, new on in, tighten the bolts. But 02 sensors are not cheap. Have you tried pulling the code yourself? It's really easy...jumper the right terminals under the diagnostics cap (right front fenderwall, beside the electrical block), turn the ignition to "ON", count the flashes, look up the resulting code. I THINK the correct terminals are TE1 / E1 but I'm going to check to be sure. I'll edit this if that's wrong. Good luck.
PS: Here is a link for the procedure for checking the sensor: http://personal.utulsa.edu/~nathan-b...01heatedox.pdf

Edit for correct terminals