2001 Montero Sport 3.5 XS rough idle and 3 codes
 

Howdy,
2001 Montero Sport has been running just peachy...155K or so...bought it 30K ago.
Last week, chain of events:
Oil change at Jiffy lube
Light comes on
Drive to parts store, read my codes please
P0111, P0101, P0107....twice each "likely a vacuum leak, might not notice anything but could experience drop in MPG and rough idle"
go home, google it...pretty much what the guy said, air intake, air temp, mass air flow, blah, blah....
Next morning - rough start, but once warm runs fine.
Hook up my small utility trailer, make planned trip....gas mileage usually not affected when hauling trailer, but this time drops to 15MPG (from standard 19-20ish)
All weekend, cold starts are rough, but warms up and no big deal.
Google again, and send list of codes to DH... but he's of the "if you're not dead on the side of the road...it's not broken" people....while I'm a "some maintenance ahead of time if there appears to be an issue can save me from dead on the side of the road"...


Anyone have experience with these codes and a Monty sport? Obvious things I can check and where those might live under the hood? I'm intelligent, mechanically minded, generally handy and not afraid to get a little dirty, but don't have a clear grasp of the "how it all works together technically" under the hood - because well, I'm not a mechanic grease monkey.


Appreciate any help. :) Heidi

The codes you have are not a result of a vacuum leak. The first two come from a malfunction at the MAF (the sensor right after the air filter). Did the oil change include the Air filter replacement? They may have disconnected the sensor and did not plug it back all the way. MAP sensor is in a different area of the engine compartment, so that one is tougher, but it may simply be a secondary code due to malfunction on the MAF side. This is something along these lines: readings from multiple sensors do not match each other - computer "panics" and tells you something is wrong here = code. Your engine most likely is running in what is called an "Open Loop" - a default set of parameters for how much fuel to add to the pistons, instead of a "Closed Loop", which is proper way to meter the fuel based on the feedback from sensor readings. That is why you have fuel efficiency drop.

Check the sensor connector on near the air filter (MAF). If you don't see anything out of place, take it to the shop and get fixed.

Ha! I love the internet!!!


Thanks Hunter! I checked and the pubescent minimum wage kids forgot to plug the MAF sensor back in at all. :mad:
Plugged it in, drove to the auto parts store and reset the codes...ta-da! All better. And Ms. Mitz sounds much better too!:D


Thanks again!
Heidi

You are welcome.
The experience you've had is the reason why I don't let anyone work on my Monty :)