Car sometimes has a very high idle and it will accelerate on its own

5

Asked by T8ertot1989 Nov 27, 2018 at 08:19 PM about the 2002 Mitsubishi Eclipse GS

Question type: Maintenance & Repair

Car sometimes has a very high idle (3k rpm) and it will accelerate on its own
in 1st gear- much more so than is normal for an automatic transmission. I
checked for vacuum leaks using the carb cleaner method. I was unable to
detect any leaks. I also attempted to clean the throttle assembly as I thought
that it might not be closing all the way.

Even though there was no Check Engine Light on, I decided to connect an
OBD ii device and got the codes P0135, P0421, and P0443. I know that the
first is about an O2 sensor, the second is something about a "warm up
catalyst efficiency" and the third is regarding the EVAP canister.

What do you all think is going on here?

2 Answers

7,455

Perhaps the air idle control valve is sticking causing excessive air flow. Would do another smoke test, clear the codes and see what comes back there. Hopefully there is no issue with the evap canister. Some people top off the tank and have issues there. Would still check all those lines in the rear as well.. Good Luck!

1 people found this helpful.
5

Any advice on how to make sure that valve doesn't stick? Also, how would I investigate the evap canister? Unsure about the historical gas-filling behavior of the driver of this car (my fiancee). Not sure if she tops it off or not.

Your Answer:

CarGurus Experts

  • #1
    dandyoun
    Reputation
    2,700
  • #2
    Daniel Foster
    Reputation
    1,280
  • #3
    T_S_T
    Reputation
    710
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Mitsubishi Eclipse Spyder
9 listings starting at $7,490
Used Mitsubishi Lancer Evolution
8 listings starting at $27,995
Used Mitsubishi Lancer
8 Great Deals out of 141 listings starting at $3,975
Used Chevrolet Camaro
20 Great Deals out of 468 listings starting at $11,999
Used Ford Mustang
42 Great Deals out of 1,603 listings starting at $8,995
Used Nissan 350Z
11 listings starting at $11,999
Used Honda Civic
204 Great Deals out of 4,033 listings starting at $1,999
Used Chevrolet Corvette
28 Great Deals out of 784 listings starting at $15,900
Used Mitsubishi Mirage
6 Great Deals out of 179 listings starting at $4,995
Used Mazda RX-7
1 listing

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.