check engine light?

today i was just heading down the interstate and my check engine light came on. nothing happened, it just came on and wont go off. the truck still drive and feels the same. what are the possabilities of what it could be? by the way its a 1996 5spd 4x4 4cyl. any help would be appreciated.

 

will this cost anything to have them check the code?

 

they will check it for free.

 

Gas cap not on correctly after a visit to the gas station perhaps?

 

banshee was right on. i had the code checked and they said it was an o2 sensor. i guess the truck can run fine without the o2 sesor working, he said that there is no need to hurry. but when i do get around to fixing it does anybody know how much it will cost. i can do the labor myself.

 

It'll cost about $80 for the sensor. You can do it yourself, but spray down the nuts holding down the sensor with PB Blaster for a few days beforehand, don't be shy with the stuff. The 2 nuts should come off after the spraying, if not, do it again.

 

Mine was a rear O2 sensor.
I bought it for $80 from a local parts store. It was a walker direct fit with the correct length wire, grommet and connector. The connector for the rear O2 sensor on my 03 2WD Taco was under the pax seat, mounted sideways, attached to the rear side of the forward seat mount frame. The nuts were rotten from sitting in a road salt filled heat shield so I brought it to a friends garage to have them put it in. He said it gave him a rough time, cutting the rounded nuts off.

Drove it for 8 miles afterwards and the light went out.

 

I hate to say it, but check dealersip prices before you run to the local parts store. My engine light came on. I had Autozone check it(free). It was the Throttle Position Sensor. A.Z.'s price was around $80, some other part stores were over $100. I figured what the hell, can't hurt to check the dealership. To my surprise, the dealer had it for just over $50, and it was a genuine Toyota part.

 

I know this is an older thread, but I just saved myself a bundle by switch...no, wait...my check engine light came on about a week after installing an AFE air filter system. I didn't notice much change in the way the truck ran, so I ingnored it for a couple weeks, until I could get around to it. Anyway, I priced the sensor at $150. After reading a couple threads about the CEL and the air filters, I decided to try cleaning the MAF with carb cleaner first, and see what that did. Cleaned the MAF, then disconnected the battery for one minute to reset the computer. When I started up, the light was out and stayed out. Not only that, but I experienced a noticeable improvement in the way the pickup ran and in low-midrange torque. Before, I got pinging during acceleration and while cruising in 5th gear. I thought it was low quality gas, but it was apparently the MAF. I suspect the oil on the filter contaminated the MAF sensor, which then relayed erroneous signals to the computer, which then caused the wrong air/fuel mixture, which caused the pickup to run poorly and the CE light to come on. I now keep a can of carb cleaner in my pickup tool kit, just in case it happens again.

So, I saved a bundle by not having to buy a new O2 sensor.

 

Don't ever use carb cleaner to clean your MAF sensor. Get some electrical contact cleaner that's plastic safe. Get a bottle of this and stash it away in your rig:

 

sounds like good advice.

 

The dealership just got finished telling me that this was the problem with my truck's fuel economy (dropped from 25MPG average to 23MPG average). They wanted to replace my MAF for some un-godly amount of money. The truck has 25,000 miles on it - not 250,000. I am going to try clean it myself and see if that helps.

Do I need to just spray it on and let it dry, or do I need to wipe it off?

Thanks in advance.

 

They wouldn't do this under warranty?

 

Somebody else suggested that we should not use carb cleaner, because of the plastic parts. He suggested an electronic parts cleaner that is compatible with plastic. He provided a pic of the can, but I forgot which thread it was on. Sounded like a good suggestion to me, although the carb cleaner didn't hurt my MAF with just the one application. I wouldn't suggest you soak it in the stuff, regardless. I just removed the air filter and sprayed it on the MAF while the truck was running. I had to keep a hand on the throttle, because the carb cleaner will kill the engine. There is a small sensor in the middle of the MAF that seems to be the critical part. I kept the rpms up a bit until I could see that all the cleaner had dried or been ingested into the engine, so I left no puddles in the intake system. Then I replaced the air filter and disconnected the car battery for one minute to reset the computer. That's all it took.

Again, I'm sure my trouble was due to the oils used on the new AFE air filter. It's been almost a month since I installed it, so I'm pretty sure it should be fine from here on out.

By the way, the previous post gave a good suggestion. Your MAF should be covered under warranty, even if you are not the original purchaser. If they gave the diagnosis and prescription, make 'em eat it. That's why people buy cars under warranty!

 

just spray and let dry, then reinstall......never touch the "bulb" or head of the sensor, as they are very delicate and can break easily.

 

Agreed, never ever touch the little wires in the sensor with anything, even a Q-Tip, that could cost you over $300 for a new MAF sensor. Below is a link on how to properly clean your MAF sensor:

http://www.4x4wire.com/toyota/maintenance/tacoma_4runner_30k/maintenancep5.html#maf
http://4runners.org/writeups/throttle/index.html

These writeups are for the 3.4L V6 and not the 4 banger, but I assume it should be pretty similar.

 

Yeah, they won't cover it under warranty because it is caused by the AFE filter - they can prove that. I am the original owner (25,000 miles in 10 months). The technician suggested that I clean it myself. He said that it wouldn't cost but a few dollars, and Toyota just says to replace it. So, if they had done anything it would have costed a shinny penny.

I have not had the chance to pick up some cleaner yet. Where should I go (AutoZone, RadioShack, WalMart?)...

 

AutoZone should carry it, if not then Pep Boys definitely will, that's where I got my can from.

 

They wanted upwards of 400 dollars for the bamk one sensor one in my 01 tacoma