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Check engine light on shortly after fuel induction cleaning

It was recommended that I do a fuel induction cleaning on my 2000 Avalon (112,000 miles). I did it and when I drove my car for a few times I noticed a delay in acceleration for a split second after hitting the gas pedal. That ended up going away and later on in the day after starting up my car again, it felt like the engine was going to stall. I hit the gas a little and drove the car and then the check engine light came up.

So, I took it in to another mechanic and they said something about Lean Bank 1 and the recommended fix was to replace the mass air flow sensor.

My question is did Mechanic 1 who did the fuel induction service screw up my car? I assume yes since the check engine light came on the same day but want to give him the benefit of the doubt before writing a bad review.

Take the car back to mechanic 1 with your complaint. Give them the opportunity to fix the problem.

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Why did you not call the first mechanic ? Whether he did something wrong on this 20 year old vehicle will be hard to prove because it could just be a coincidence . At least see what he has to say before you post a bad review .

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Could a fuel induction cleaning leave residue or whatever on a part in my car causing an issue?

When doing an induction cleaning, the intake hose is removed from the throttle body.

If there’s an intake air leak for whatever reason after the MAF sensor, it will set that code.

Tester

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When the mechanic called me I believe he said they didn’t see a leak but something was clogged up. I’ll get clarification when I pick up my car. I was just thinking that the debris from the car got moved from one section to another causing an issue.

Unlikely. A lean fuel condition is caused by air getting into the engine through a path not through a device called a mass air flow (MAF) sensor. A leak. Possibly from a hose from the MAF to the engine that got pushed out of the way to allow the cleaning. Either it cracked or did not get put back into place correctly.

Take it back to mechanic #1 and let them take a look.

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Are there any other sensors that could have been damaged by an improper cleaning?

You have received excellent advise thus far.

If you feel up to it… remove the negative batt terminal from the battery for 2 min or so and reconnect

See if the light comes back on… it may …it may not

If it does… it goes directly back to mehanic number one… give them a chance to look over what may be causing this, they should know what to look for. I know i said “should” but… im trying to be nice today :slight_smile:

Update:

I got the car serviced by mechanic 2. I was afraid to go to mechanic 1 because I thought they may mess more things up or try to upsell me. When I went to mechanic 1, all I wanted was an oil change. He said that I needed new front and rear brake pads and recommended the fuel induction service. I never had an issue with my brakes but according to my records- I have only had the back brakes replaced with the car at 48,500 miles (When I bought the used car) and when he replaced both brake pads my car was at 113,559 miles. After the brake pads were replaced, I noticed the brake pedal to be softer than before. Is that normal and will it firm up after using my brakes for awhile (The pads were the only thing replaced)?

Mechanic 2 told me the check engine light code was P0171 fuel trim too lean bank 1. Performed testing and no vacuum leaks found, removed MAF sensor and found very dirty, cleaned MAF and fuel trims returned to normal ranges. Suggest replacing MAF sensor.

I asked if the fuel induction service would have caused this problem and the person behind the counter told me no but that the MAF sensor should have been cleaned. Now I wonder what all Mechanic 1 cleaned (if anything).

I’ll update if more problems come up.

just out of curiosity, was mechanic 1 a chain store, i.e. lube or tire shop?

No sir. A lean condition can also be caused by lack of proper fuel delivery, i.e. weak fuel pump, clogged fuel filter or injectors.

Yes, I know. Re-read the original post. Given what he had done, what’s more likely? The fuel pump, injectors or filter spontaneously clogged? Or the intake hose was cracked or mis-installed after a fuel induction clean?

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The first time I had the check engine light on was shortly after driving the car when it felt like it was going to stall when starting it up (The light came on at like 30-40 mph). Then I had the codes cleared and drove for a few days at the same speeds and had no problems but when I went on the interstate at 65+ mph the check engine light came on again. Any idea why the check engine light came on at low and high speed?

As for driving with the new MAF sensor, I took it on the interstate today and no check engine light. Hopefully no more car problems.

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