Hi,
Long time lurker and first time poster. My names Robert and im living in las vegas right now. Im hoping someone might be able to point in the right direction.

I recently had some issues with the truck not going far, i could hear it clogged up turned out i hit something and it flattened my cat. so i went ahead replaced the cat, o2 sensors and plugs. Now the truck runs good in gear but at idle is when it acts up. I dont have a tach so i cant tell you the eact RPM's but at the low end it idles where it should but its up and down non stop as soon as it hits the low it kicks up. If i put it in gear and slow the RPM;s down by letting the clutch out a bit it will stop the up and down and settle with a very fast idle.

Truck:
2000 tacoma 2.4l 2WD

thanks in advance
Robert

 

Are you sure you didn't damage anything else? I'd crawl under there and inspect everything, there could be other damage to the engine/exhaust system.

 

i dont think there is another issue because oddly enough i ran about 2 days before the cat clogged and it ran fine. i did remove my entire exhaust last night because the o2 sensor was being a punk and not coming out. everything looked good down there.

 

forgot to mention i swapped my MAF as well.

 

Need a little more info please-
Have you reset the ECU (disconnected battery) since swapping Cat and MAF?
Was the new MAF OEM?
Are you throwing any CEL's?

Last time my idle wandered it was the Throttle Position Sensor.
With the fuel mods you have done I wonder if your ECU just panics and jumps to open loop?

 

yea i left the the battery disconnected for about 3 days to reset teh ECU, no CEL will hit it with the code reader to see if there are any pending codes when i get home.

MAF was from autozone brand new (not saying that means its good just saying its new)

where is the TPS and how would i diagnose a bad one? I have access to multimeters and other tools just learning alot of things as i go.

 

TPS is in the throttle body. Should have a three wire harness attached to it. Pretty cheap so I didn't bother even diagnosing it but this may help:
http://www.enduringautomotive.com/tps/

 

might have to do that. Ill prob run it for a week to see if the computer is just getting a new map and if it doesnt change ill pull the TB out swap the TPS and clean the IAC.

 

Check long and short term fuel reading when you scan and report those numbers.

Aftermarket MAF's on most cars typically end up causing issues. You still have the old one? If it is good swap it back in and see if that helps. Not sure if you replaced as part of the exhaust and o2's or if it was diagnosed as bad.

Could be a vacuum leak. I would think if it is hunting that bad you would be albe to hear the leak if you have one.