Q: Hello, James. I just finished reading one of your articles and was hoping you could help me on a problem I am having with my 2014 Corvette with an automatic transmission.
I have had the car to the repair shop several times for a check engine light. The fault codes that they find every time I take the car in are P2096 and P2098, which are fuel trim problems. They have told me every time that they could not find any reason these fault codes could be setting. The last time this happened I took the car to a friend who has a shop across town and he told me the exact same thing my local shop has been telling me.
Do have any suggestions? I am concerned that the car is running lean for some reason, like a weak fuel pump, and if I continue to run the engine lean I am worried I may damage the engine.
These fault codes are for Bank 1 and Bank 2, can you tell me what Bank 1 and Bank 2 are?
A: I think I can help you out Matthew, but you may find the answer a bit odd.
Let’s start with what Bank 1 and Bank 2 refer to. Bank 1 is the grouping of cylinders of the engine that has the No. 1 cylinder. For the Corvette, this would be the driver-side. Bank 2 would then be the passenger-side of the engine. Sensor 1 on the Corvette engine is always the sensor closest to the exhaust port of the engine. Sensor 2 is post catalytic converter.
Diagnostic trouble code (DTC) P2096 and P2098 descriptions
P2096 is the Post Catalyst Fuel Trim System is at its Low Limit Bank 1.
P2098 is the Post Catalyst Fuel Trim System is at its Low Limit Bank 2.
This simply translates to the engine controller is seeing a lean condition (too much air and not enough fuel). The engine controller is constantly monitoring the post catalyst air/fuel ratio to determine if the catalyst fuel trim is out of range.
The potential remedies/fixes for these fault codes can include:
Check for low fuel pressure.
Check for a clogged fuel filter.
Check for a failing fuel pump.
Check for a leaking or failed fuel pressure regulator.
Check for a clogged or leaking fuel injector.
Check for a rough running engine due to a misfire.
Check for a worn, cracked or fouled spark plug.
Check for an ignition coil that may be failing internally or water in the spark plug well.
Check for a clogged catalytic converter.
Check for an additional fault code P0421 (catalytic converter efficiency below threshold). If you have a clogged catalytic converter the vehicle will be slow to accelerate and slow to build rpm. There may be a hissing noise under acceleration.
Check for a faulty mass airflow (MAF) sensor, which uses a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture.
Check for a clogged air filter.
Check for a loose clamp on the intake inlet tube between the mass air flow sensor and the throttle body.
The barometric pressure read by the mass airflow sensor
Different altitudes will have different barometric pressure readings. For example, at sea level the barometric pressure will read between 29 and 31.
|Barometric Pressure Chart|
Check for a large vacuum leak, which is unmetered air that enters the intake manifold resulting in an overly lean mixture. Usually you can hear a hissing noise if you have a vacuum leak.
Check for an exhaust leak, which would cause the oxygen sensor to read incorrectly.
Check for cracked exhaust manifolds.
Check for damaged exhaust manifold gaskets.
Check for a faulty oxygen sensor. The last thing to expect is a faulty oxygen sensor, most of the conditions listed above can cause the oxygen sensor to give a false reading.
So, here it comes Matthew. Any good repair shop most likely has checked for the conditions listed above. The most common reason for the fault codes listed above is when the driver continuously taps the accelerator pedal (on – off – on – off – on – off) to try and maintain a constant speed, or possibly keeping the beat to a good song. I suggest clearing the fault codes and try to keep the accelerator pedal in one position as much as possible and see if the fault codes return. There’s another option Matthew, you could try listing to talk radio. Let me know how this works out. Vette
Photos by James Berry