Q: My engine light keeps coming on. We have replaced the air/fuel ratio sensor four times.

asked by on October 30, 2016

we have our air/fuel ratio sensor now replaced 4 times in 1 year( 1 at our charge) , clearned the code p2a00 in the computer, relearned it in the system but still the engine light keeps coming on. we went to different garages but they can't seem to find whats wrong. we had the air intake bellow boot replaced because of It was ripped. cleared the code again and now after 1 week the light comes on AGAIN. where can we look what might causes the sensor to go off every time?

My car has 148000 miles.
My car has an automatic transmission.

Fuel Injector Replacement $400.56 - $3968.30 Get a Quote
Check Engine Light is on Inspection $94.99 - $114.99 Get a Quote

Hey there. As you may know, this may be caused by a few different things, one of which is a faulty sensor (which you have already replaced). This may also be caused by an intake air leak, leaking or dirty fuel injectors, or low fuel pressure. These types of problems will cause an unbalanced air/fuel mixture to be supplied to the engine resulting in poor performance, rough idling as well as causing the Check Engine Light to come on. Bring up this possibility with the previous garages or have a certified expert from YourMechanic diagnose the Check Engine Light in person so that this can be properly repaired.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Possible wheel bearing problem
Hub bearing failures are common. The description you gave is very typical of one. Bad hub bearings can sometimes vary in noise intensity when you turn left or right. This happens because more pressure is put on the bearings during...
2003 Mini Cooper struggling getting into reverse, unles going into third gear first
It's pretty common with these Minis. You might have the shifter bushings checked. Maybe the bushings are starting to wear. But those Minis are not the greatest built vehicles. As they age, they get all kinds of problems. I would...
No gas getting to the engine
The easiest thing to check is to listen to the fuel tank when the engine is cranked to see if you hear the fuel pump run. If you hear it run, then check the fuel filter for it being clogged....
My car keeps stalling - 2012 Ford Escape
Hello there, stalling issues with your 2012 Ford Escape can be caused by many faults. The most common faults are the MAF sensor, vacuum leak, oxygen sensor, fuel pump, or crank position sensor. I am unsure what you mean by...
Power locking,and unlocking with remote does not work
Hello there, you have several different issues going on with your 2006 Acura MDX. When the window regulator is replaced there is a window reset procedure that must be done, this tells the regulator when the window is fully closed,...
Car oftentimes doesn't start, when it finally starts it doesn't stay running.
Hello there, many common faults will cause your 1989 Oldsmobile Cutlass Supreme to have a hard time starting and die after it starts. You have done great in replacing the crankshaft position sensor, fuel pump, fuel filter, and ignition module...
My 2002 Buick Regal no dash lights and no tail lights
Looking at the wiring diagram for this vehicle, it does not appear that these two items share a common ground or fuse. These appears to be two separate problems. The instrument clusters on these vehicles are known for failing internally....
I'm ready to buy a 2004 Chevy Silverado but chk engine light shows Knock Sensor. Also Oil Pan Leak, Fr Axle Seals Leak. Buy? Cost?
Hello Mike. You have found yourself in a position where there is a lot to consider, and the choice is going to come down to how much risk you are willing to take with this truck. Starting with the knock...
So I have a 2006 Chevy Cobalt LS (used) with roughly 870,00 Miles. I have been driving it for about 2 months now. All of a sudden
Hi Amie. Thanks for contacting us today. A rattling noise like you have described is often caused by a loose bracket, belt or pulley. On the driver side, a power steering pulley could be the source of this noise, while...

Related articles

Symptoms of a Bad or Failing Catalytic Converter
Common signs include reduced engine performance, rattling sounds, and the Check Engine Light turning on.
P2066 OBD-II Trouble Code: Fuel Level Sensor “B” Performance
P2066 P2066 code definition Fuel Level Sensor “B” Performance What the P2066 code means P2066 is an OBD-II generic code for the engine control module (ECM) detecting the fuel level sensor “B” performance. The sensor output voltage is not accurate...
P0344 OBD-II Trouble Code: Camshaft Position Sensor Circuit Intermittent
P0344 means that signal is missing at one point or another at the camshaft position sensors. This is usually due to an electrical circuit fault.