Skip the auto shop - Our mechanics make house calls

Q: After replacing valve cover gaskets, car runs horrible, and throws 5 different codes.

asked by on

I did a cam cover gasket job on my 2003 cadillac cts with the natural aspirated 3.2l engine. It seems sealed up fine now, used to leak oil on the exhaust manifolds, stunk, and smoked worse and worse over time. Everything is back together, but it runs terrible. I get 5 check engine codes: P1779, P1791, P2105, P2123, P0700. I didn't have any codes before I started this job. All the vacuum lines appear reinstalled correctly, all the connectors seem OK at least on the outside. Wondering if I have a broken wire on a connector, and which one that might be. The two big connectors to the ECM were off, I haven't checked to see if I might have a bent pen. . Hoping someone out there in car mechanic land might have an idea of where/what to check next.

My car has 152000 miles.
My car has an automatic transmission.

Hi there. Look on the engine for any ground wires. There could have been a ground wire that was disconnected to remove the valve covers causing all of the codes to appear. A ground that is not hook up can cause electrical components to fail and not function. If you need further assistance with your check engine light being on, then seek out a professional, such as one from Your Mechanic, to help you.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • After replacing valve cover gaskets, car runs horrible, and throws 5 different codes.

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: how many spark plugs does a cadiliac cts 2017 have?

This engine has one spark plug and coil per cylinder. This is a 4 cylinder engine. Has 4 spark plugs.

Q: VSC Light

If the VSC light came on, then you may have an issue with one of the speed sensors causing the system to engage. The ABS light may not come on if it does not recognize a sensor problem. Have the...

Q: Car has been randomly sputtering/hesitating when driving on the road.

Hi and thanks for contacting Your Mechanic. Bad fuel or too high of a fuel rating will cause a sputter problem. Fuel that has been sitting for a while and is not regularly added by fuel trucks will have excessive...

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...