Q: Flashing CEL

asked by on

When i start my Audia4 up the engine is rough and the car is shaking and the CEL flashes. I took it to auto zone and have the following codes. p0304, p0171, p0301,p0300. Ive been driving my moms car because i don't want to drive the audi and the audi is also leaking oil. Before all of this happened i took my car to the mechanic because my CEL was on and they charged me 600 for a new fuel injector. but now present today my CEL is flashing . i went to Oreillys to get new coils and i changed all 4 of them but it still flashes and the car is rough so I'm not sure what to do . i don't have much money for a mechanic or the dealership. and i can't trust anyone expect for the dealership but thats going to be really expensive.

My car has 128000 miles.
My car has an automatic transmission.

The codes you recorded, P0304, P0171, P0301, P0300, all pertain to engine misfiring. The flashing of the Check Engine Light signifies that the misfiring is "active" (ongoing) and consequently you should try to get the car repaired before operating it further and possibly damage the catalytic converter.

Ignition coils have to be tested before they are condemned. If you did not test them, it may be that the old one were perfectly good. It is best not to replace any parts until you either pinpoint the exact fault or work with a professional to get that diagnosis. Lots of times, perfectly good parts are replaced, without testing the parts, and that is needless nowadays with the availability of not only detailed Factory Service Manuals but mobile certified technicians such as those dispatched by YourMechanic.

Here is a list of the possible faults that a mechanic would check with the codes that you have:

If you seek a diagnostic, the technician from YourMechanic will walk you through a sequence and following is a partial list of some of the items that are relevant to the codes you recorded. Note, again, that any part that is identified has to be SEPARATELY diagnosed. That is, it is never wise to replace a part just because it is on a list of possibilities associated with a code.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Flashing CEL

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: Rich idle only, negative STFT

Some common causes of too much fuel being delivered in a situation like that you describe are: a faulty coolant temperature sensor (the temperature signal is a part determinant of injector pulse width); leaking fuel injector(s) allowing too much fuel...

Q: Fob won't open driver door without using key

It sounds like the most likely cause of this fault is the driver's door lock actuator. When these fail, they will only function when used manually with the key. A qualified technician, such as one from YourMechanic, will be able...

Q: largest motor for 2008 chevy cobalt

The hardware and software of the computer (powertrain control module) and transmission control module (TCM) in the Cobalt will only work with your present engine. If you change the engine to one that is not a catalog interchange for the...

Related articles

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.