Skip the auto shop - Our mechanics make house calls

Q: What would make all three plugs on bank to foul out?

asked by on

Truck has a new crate motor with actual miles of only 3500 new plugs wires sensors etc. The truck just started misfiring at cruising speed. It is showing misfire on number two cylinder, I pulled plugs checked all the wires wires are fine. Question is all the plugs on bank to our fouled but all the plugs on bank one look perfect. The truck cranks up fine and holds feel pressure at 55–60. It starts miss firing wants the engine is warmed up and I start cruising down the road. also I checked the EGR valve and did not really see anything wrong with it. I also checked for vacuum leaks and could find none. Thanks for any help or info you might have for me. I also replaced all three CO2 sensors about two weeks after motor was put in .

My car has 156000 miles.
My car has an automatic transmission.

A: From what you’ve described, you’ll need to ...

From what you’ve described, you’ll need to have the fuel pressure tested to make sure it holds after tuning the key off. If the pressure drops then you may have a leaking fuel pressure regulator. If pressure is okay then test the O2 sensors to make sure they are working and not shorted out. If you need some help with these checks, consider YourMechanic, as one of our mobile experts can come to your home to diagnose the misfiree and help you make the necessary repairs.

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!

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: Fuel pump fuse and relay problem.

Located inside of the fuel tank is a fuel pump that requires amperage to operate. This pump can have an electrical failure that causes it to use more amps than the system is set up for. The fuel pump over...

Q: 2007 Dodge Grand Caravan hard detonation problems

Take a compression tester and check the compression of each cylinder. This will determine how much pressure will hold in the cylinders. If the pressure is 120 or higher, then the cylinders are okay. If the pressure is lower than...

Q: It takes two or three tries to start the car.

Hi, thanks for writing in. I recommend testing the fuel pressure and monitoring the pressure after the key is turned off to see if the pressure drops to zero. If it does, then the system will need to be tested...

Related articles

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...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...