Engine codes

[gamiller]

thermostat <> water pump.

yes, some people advocate replacing the water pump with one that has a metal impeller; however, your code is not suggesting that the water pump is the problem.

any brand thermostat will do; i'm fairly sure that all are made of metal. feel free to comparison shop... or simply get one from the nearest parts store.

[brpavers]

You dudes rock. I have been fighting with the P401 Code for months and could not pass emissions (though the emissions were fine). I found this thread and checked the throttle body passages like 'thelaststand1984' suggested and eureka that thing was clogged up big time. I cleaned it with a small screwdriver, a piece of 'weed whacker' cord (for the passage to the EGR, and lots of cleaner. I put it back together, started it up and got three more codes: lean bank 1, lean bank 2, and insufficient catalyst flow and i about had kittens until it occured to me that it was probably from the all throttle body cleaner I used. I cleared the codes, passed emissions and I have drove it over 1000 miles with no returning codes, Yeahya.

Hopefully it will stay off, but who cares for another year.

On a side note, it went from 22.2 mpg to 24.1 mpg driving in the burbs as quickly as possible. Not bad returns for a couple hours work on my 2000 Cat w/ 2.5 ATX.

Thanks a million NECO dudes.

[skater]

Glad we could help...and welcome to NECO!