Skip the auto shop - Our mechanics make house calls

Q: codes p0101 and p0303 simultaneously

asked by on

I continue to get codes p0101 and p0303 when throttle is near wide open on highway on ramp (60-70mph). The fuel pump, filter, plugs, wires, cap, rotor, injector spider, and delco ecm have just been replaced in an attempt to correct this condition. The engine runs smooth until this speed, when you can feel a shudder and the check engine light illuminates. Cylinder 3 has 185 psi compression check, and continuity was checked on ecm etc.

My car has 240000 miles.
My car has an automatic transmission.

The code P0101 is for a problem with the MAF sensor and code P0303 is for a cylinder number 3 misfire. The first thing to check is to make sure there is no vacuum leaks or leaks between the MAF and the throttle body connection hoses. The MAF may be giving an incorrect input to the computer causing the misfire and MAF code. Have the MAF code pinpoint test done and replace the MAF if it fails the test.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
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

Get a quote

What others are asking

Q: My yukon is running like nthere is something terribly teribly wrong

The mass air flow sensor measures the speed of the air going into the engine. The P0101 code could be an electrical issue. The PO449 code is related to fuel tank emissions. Codes give you the area of a fault...

Q: Window malfunction

Hello. Thanks for writing in about your 2006 Chevrolet Express. When windows quit working, this is usually due to a faulty window motor and regulator. Another possibility is that there is a problem with the window switch. Sometimes there are...

Q: Can't pass smog check due to misfire

If your engine is misfiring it will not pass a smog check. The engine needs to be in good running condition in order to pass. I suggest having an expert mechanic, such as one from YourMechanic, inspect why your engine...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.