Ok, I've had a CEL for about 4 months now on my 00' 4Runner w/ 76Kmiles. It popped up during some "spirited" driving when I was running late to a meeting (85-90 mph speeds).

During the 4 months:
- my mileage has not suffered at all (21 mpg in 60% hwy / 40% city driving)
- I've cleaned and inspected the MAF
- Checked gas cap seal
- Haven't checked 02 Sensors (but seriously doubt they're bad due to the uneffected gas mileage

Other than the annoying CEL, the vehicle drives just as it always has. No idle issues, no stalling, no bucking, nothing...just smooth like always.

So give me some other common areas to check? Throttle Pos Sensor maybe? The Autozone guys here are worthless and I'd like to avoid dropping to $75 at the Stealership to pull the codes (if i can help it).

 

If you jump 2 pins on the diagnotics port the CEL will flash the aproprate code and you can go from there.

If you REALLY dont care about it just pull the ECU fuse for a few secs and that will reset the puter. If your light comes back on you know you have somthing that needs looking into, otherwise perhaps it was just a glitch.

see http://www.off-road.com/toyota/tech/codes/ for more info

 

just go to Autozone, have them pull the code and post the results from the printout of what code is stored on here and we can help from that info. Just because they are worthless don't pass up the oppertunity of a free scan.

 

That only applies to the pre-ODBII ECUs, the 3rd gens will have ODBII and you need a code reader to pull those codes. Many auto parts stores will read the codes for you or invest in a code reader and pull them yourself.

 

DOH 2000 year, my bad

 

Without an actual OBD code number it is frivolous to speculate on what it could be.
Get the number pulled or get a cheap reader and pull the code and post it here for help.

Cheap reader:
http://www.harborfreight.com/cpi/cta...emnumber=46030

 

Will that code reader fit the specialized Toyota pin-out? That's the problem I've had so far. I have a code reader for my Vette, but it is not compatible w/ the Toyota. I already stopped at 2 Autozones...they didnt have the correct adapter either (hence my 'worthless autozone' comment).

I don't mind buying a reader, but i want to know for sure that it will in fact work.

 

You can visit the code reader manufacturer's web site for the one that you have for the Vette as long as it is OBDII 1996 and up code reader. They should have a reference for which adapter you need for the Toy if there is one.

I always thought all of the OBDII connectors had to be the same configuration for ease of use? Which connector are you trying to use? The OBDII connector is located inside the truck in the drivers area (not exactlly sure where i.e, under stearing colum), not in the engine bay. If you already know that I appologize but just wanted to make sure.

 

Ok, I got it pulled: P0171 Bank 1 lean condition

That sounds like an 02 sensor issue. But is bank 1 the right side front 02 or the left side front 02?

 

Clean the MAF, not just the IAT bulby thingy but the actual hotwires.
https://www.yotatech.com/attachment....achmentid=1361
https://www.yotatech.com/attachment....achmentid=1362
or here
http://www.4x4wire.com/toyota/mainte...tenancep5.html

 

A 4runner only has 2 O2 sensors so they are bank 1 sensor 1 and bank 1 sensor 2, both can be found near the converter. As Unhappy99 mentioned it is more likely that your MAF needs cleaning. Do that first and see if it clears the code.

BTW I am not sure what you mean by a certain connector for OBD II. The OBD II interface is standardized so any OBD II reader should fit the connector.

 

Ok, after much searching, I found the OTHER diagnostic port under the console. So what the hell is the underhood diagnostic port (labeled "DIAGNOSTIC") for? Everyone on the "other" 4Runner-Forum told me that was the port . Regardless, I found the OBD port and pulled the code.

After a bit more searching on here for that code, I realized another goof that I made (once again based on info on the "other" 4Runner forum). I was cleaning the "resin" bulb thingy on the MAF, not the actual MAF sensor wires that are hidden down in the sampling tube. So I just came in from outside...I cleaned the actual MAF wires this time, and then disconnected the battery. Upon start up, the idle was a bit choppy from the re-learn (and probably from the cleaning spray residue) but after a quick trip around the block, she is purring like a kitten again. I'm gonna drive it for a few days to see if the CEL returns. If it does, then I will purchase a MAF off of Ebay or somewhere.

In the meantime I think YotaTech will replace the "other" 4runner forum in my Favorites Menu. Thanks for the help guys!

 

There is no other forum. There is only Yotatech.

The Diagnostic port in the engine compartment is for checking timing, turning on the fuel pump, and a few other goodies while you are diagnosing crude engine problems.

The OBDII port is the one at your right knee, and used for monitoring engine and emission performance.

Congratulations Ebbs. I have complete confidence your CEL will not return, at least for another 1.5 years. I've gotten into the habit of cleaning my MAF annually along with the oil change.

 

That diagnostic port is for engine diagnosis and only fits a propritary connector.
Glad you found the OBD II port and solved your problem!