'03 2500 Hd Check Engine Light On

star2323 · September 5, 2008

I have an 2003 2500 HD Silverado with the 8.1 and Allison. It has 57,000 miles. The check engine light is on and when you start the truck up it says "Check Oil Level" in the display area in the dash. The oil level is fine. I have a scanner so I scanned it and the code is PO332 which is the passenger side knock sensor. So I replaced the knock sensor in case the sensor was bad. This did not fix the check engine light coming on. I can clear the PO332 code with my scanner but after driving the truck for 30 minutes or so the check engine light comes back on and reports the PO332 code again.

I just had the oil change and I was talking to the guy at the shop about the check engine light. He thought the truck ran sluggish for an 8.1 and thought it could have something to do with the check engine light and the "Check Oil Level" message being on. He suggested I take it to the Chevy dealer and have them check it out.

I think the truck seems to run fine and I never thought it was sluggish but I have never owned a 8.1 or even an 6.0 before so I have nothing to compare it to.

What do you think? Could the PO332 code, "Check Oil Level" message, and sluggish performance all be tied together? Any way I can tell if the engine is running sluggish with nothing to compare it too?

C6Racer · September 9, 2008

Well, when the knock sensor tells the PCM (computer) that the engine is pinging then it will retard the timing. This would lead to sluggish engine performance and poor fuel economy. Have you ever used any fuel system cleaner? If not, I suggest you do so. I hear Chevron Techron is among the best stuff. There's also an AWESOME product called Sea Foam that you can get at any Kragen or Auto Zone. You need to follow the instructions which involves pouring the product through a vacuum line. I used the brake booster line on my truck. Your truck, however, may have a HydroBoost unit so you will need to find an alternative. You may need to get creative. I suggested these products because there may be foreign material in one or two of the cylinders causing the fuel to ignite prematurely, which is what causes pinging. As for the engine oil level, I would make sure the oil level sensor is plugged in correctly. I'm not sure about your truck, but on mine the sensor is a thing that sticks out of the passenger's side of the oil pan under the starter. Make sure the connector is free of dirt. I like using electronics cleaner that is available at said auto parts stores. Hope this helps. Good luck!

star2323 · September 9, 2008

Thanks for the reply. The MPG never has dropped off. I'm getting around 11-12 which I believe is pretty common for the 8.1. I have the truck in at the Chevy dealer right now. Last I talked to them they the wire which went to the knock sensor was broken but they had not located the broken wire yet. I have a feeling this is going to be an expensive fix. The check oil level deal doesn't sound as bad and is something I can probably do my self even if I have to replace the sensor.