Q: Check Engine Light coming on after repair to fix it

asked by on

We had our car looked at, due to the Check Engine Light coming on, which was due to error code P0400. The mechanic inspected the car and said that it needed a new EGR valve. We set up an appointment to have that done, and upon arriving and looking at the car further, the same mechanic said that the EGR valve was fine, but the car needed a new EGR solenoid. We set up a third appointment to have this done. After replacing the part and resetting the codes, the mechanic said that the issue should be fixed. A few days later, we took the car for a drive and the Check Engine light came on again.

Some of these vacuum-operated EGR systems that your vehicle has can be a little tricky. There are a few different solenoids, and they can be hard to isolate and test to find the bad component. In addition to the solenoids, the EGR passages in the intake manifold and exhaust manifold can be clogged with carbon deposits as well. This would also cause your EGR system to set a code. I would ask for help from a mechanic at YourMechanic to look over your vehicle, diagnose the current cause of your Check Engine Light illumination, and make any necessary repairs to your EGR system.

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. Check Engine Light coming on after repair to fix it

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: Stalling and grinding

The grinding noise may be a number of things, but is often times associated with the a starter that is beginning to fail. When this happens, sometimes the starter gear that engages the flywheel remains engaged too long resulting in...

Q: Transmission problem 1998 Ford Explorer

Hello. The most likely cause is with the shift solenoids in transmission and/or valve body components. It is also possible that you could have an external electrical problem because the PCM also controls shift points. However, the most common...

Q: My car cranks but won't start sometimes

This may be caused by a number of things such as leaking fuel injectors or potentially a faulty ignition coil(s). Coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeated as the...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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...