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DaveTheCarGuy, Car Enthusiast
Category: Car
Satisfied Customers: 240
Experience:  AAS in Automotive Technology.
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suzuki grand vatara: 1999 Suzuki grand vitara 228000 mi. ran

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1999 Suzuki grand vitara 228000 mi. ran fine would sometimes shut off , start right back up, cleaned maf worked ok for a few day's then again threw code 102 took to shop they replaced maf sensor now backfires when cold gets better when warm?

DaveTheCarGuy :

Hello, Code P0102 is Maf low input. This code can mean more than just a MaF problem. It is the computer saying that the engine is getting more air than the maf is reading. This can be a clogged intake, a leak in the intake piping, or another airflow issue. Start by checking your intake piping for obstructions or damage. Focus on the area after the maf. If you don't find the issue

DaveTheCarGuy :

If you don't find the issue in the intake pipe, check all your vacuum piping. If you don't find the issue let me know.


what about the backfire and it ran fine before the maf sensor was replaced?

DaveTheCarGuy :

Backfires can be caused by any fueling issue; too much, or too little and you can have backfire situations. Are you sure that it is a backfire and not a misfire?

DaveTheCarGuy :

Also, they may have reset the PCM to clear your code after replacing the maf. This will also reset the fuel trim adjustments that your car had learned. This may have uncovered an issue that had been covered up by the cars adjustments.

DaveTheCarGuy and 9 other Car Specialists are ready to help you
Customer: replied 4 years ago.

I already knew what po102 is, what about the backfire and running better when warm

It sounds like you have a vacuum leak past the Maf. What this allows is more air then expected into the combustion chamber. As far as the running better warm and the backfiring; A car needs more fuel when cold then when warm, so if you have a fuel shortage (like one from a vacuum leak or past maf air leak)it will run worse when cold than when warm(when it needs less fuel). The backfiring can also be caused by this issue in two ways:
Way 1 - There is not enough fuel in the air to be ignited by the spark, but once it gets into the exhaust manifold it ignites, this causes a back fire out the exhaust.

Way 2- The cause is the same as way 1, but it happens during the very small amount of time that both valves are open and it backfires into the intake (the intake has less pressure so it will head there over the exhaust if it can)


Is the car running better? If you have any follow up questions or need more help with this one, please let me know.

Customer: replied 4 years ago.

car is running fine . I think it needed to re-learn some settings. Thanks for your suggestions.


I'm glad its running better. Ill be here if you have any questions.


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