Answer: Your car is equipped with a electronic throttle control. So there is no adjustment. The idle speed is determined from the ECM. You need to scan your car for trouble codes. A oxygen sensor or Mass Air Flow has probably shorted and needs replacing.

Question:   2002 Toyota Camry mileage: 70,000.  The car has a rough idle when in "drive" (auto trans, A/C off). In Neutral, it is barely noticeable.  While driving, it is fine.  Only when I come to a stop does it shake.  It had a major tune-up (cap, rotor, wires, plugs, filters, timing, etc.), injectors were cleaned - no difference.  The dealer is at a loss and so am I!  HELP!

Answer: Your car is equipped with a electronic throttle control. So there is no adjustment. The idle speed is determined from the ECM. You need to scan your car for trouble codes. A oxygen sensor or Mass Air Flow has probably shorted and needs replacing.

Answer: Replacing the oxygen sensor should fix your problem.

Question:  1999 Chevy Impala mileage: 127,000.  I have taken my car to three different mechanics to have this problem solved and have yet to get it lined out.  It has extreme hesitation on the throttle, and when the car slows from normal driving speed to a stop it dies.  The idle does run rough whereas before this problem occurred it purred like a kitten.  I've replaced the computer, map sensor, throttle position sensor, starter relay, and according to the Chevy Dealer they are not getting any new readouts of problems.  I'm running out of options on this problem.  I'm hoping you may have an idea of what to do. 

Answer: Check the EGR valve to make sure it is closed at idle.  Inspect the engine for vacuum leaks and check the exhaust system and catalytic converter to see that they are not plugged.

Question: 1998 Ford F-150 4 WD mileage: 114,000.  My truck problem is ROUGH IDLE, POOR GAS MILAGE, HESITATION, after a short drive (10 miles) or so, if I shut the engine off and restart, the motor is hard to start and about 1 mile down the road the check engine light comes on.  I took my truck to several mechanics and have replaced the THROTTLE POSITION SENSOR, 02 SENSOR, WATER TEMP SENSOR, They got me an Emissions sticker but the problem still remains.  I recently used the truck's self-diagnostic tester and the following results (codes) were obtained.  KOEA: 31-EVP circuits below minimal voltage.  KOEA: 32-EVP voltage below closed limit.  KOEA: 33-EGR valve not opening.  KOEA: 41-O2 sensor not switching.  RUN CODE: 21-No idea what this one means!  RUN CODE: 44-Secondary air inoperative.  RUN CODE: 33-EGR valve not opening.  I'm just an idiot trying to follow a Haynes manual, and not sure where to go from here, and need some advice!  Please Help- the cost of gas is killing me!  Thanks for the help!

Answer: Reset the computer, then turn the key on to see if any immediate codes are present, if so then repair as primary codes warrant. If nothing comes up start engine and recheck system. what we are testing for in this problem is to only repair the most prevalent coeds as it can create the other secondary codes. Then check the fuel injector resistance to be sure one is not shorted.  Check fuel pump pressure and fuel pressure regulator.

Question: 2000 Isuzu Pickup 4x4 mileage: 46,000.  It is in great shape. Recently when slowing down for a stop, push clutch in and idle speed picks up and then goes down 3 times before becoming stable.  Sometimes goes from 800 rpm to 1500 rpm.  Have replaced plugs, filters, wires, O�, and scanned computer with no error codes.  Cleaned throttle body.  Checked for vacuum leaks.  Posted this on a newsgroup and at least 4 other people have had the same problem.  Suspect a sensor, but not sure how to tell.

Answer: Check the EGR valve to see that it is closed at idle.  Check for a vacuum leak in the power brake booster.  Check for a plugged catalytic converter.  Check for leaking fuel injectors.

Question: 1999 Honda Civic  mileage: 60,000.  Recently the idle has become very sporadic.  As soon as you start the car the idle will jump from 700 rpms to about 3500 rpms it will hold and then go back down it does this over and over, it will do this whether the car is hot or cold.  What is causing this?  Please help!

Answer: Your car is equipped with a electronic throttle control. So there is no adjustment. The idle speed is determined from the ECM. You need to scan your car for trouble codes. A oxygen sensor or Mass Air Flow has probably shorted and needs replacing.

Question: 1999 Chevrolet Lumina mileage: 106,500.  Vehicle runs fine down the highway, but after exiting and idling, it "misses" and at times smells rich.  Replaced TPC and gas filter.  Some improvement.   While engine was running rough performed an adjustment to the EGR (i.e. tapped it slightly with a wrench) and problem cleared up.   Vehicle ran fine for 2 weeks and now the same is happening.  Again, tapped on EGR and problem seems to be corrected.  Should EGR be replaced or can it be cleaned/repaired?  Also, could the oxygen senor be part of the problem?

Answer:   It is probably time to replace the EGR valve.  If a major tune-up has not been done recently, this could be the cause of your problem.  Replace the spark plugs, plug wires, fuel and air filters, etc.   Also, replace the oxygen sensor.  In addition, service the fuel injection system.  Clean the carbon deposits from the throttle bore and idle passages.

Question: 2003 Ford Explorer mileage: 42,000.  My car misses and idles very roughly.  The idle will drop down suddenly from about 900 rpm to 400-600 rpm then pops back up again.   It has had degrees of this symptom for a few thousand miles, possibly dating back to when the battery failed and had to be replaced.   A dealer tune-up and a couple bottles of gas treatment have not made things any better.

Answer: Your car is equipped with a electronic throttle control. So there is no adjustment. The idle speed is determined from the ECM. You need to scan your car for trouble codes. A oxygen sensor or Mass Air Flow has probably shorted and needs replacing.