Hey guys
I have a 2003 Honda Accord LX that I just bought. The car had an AC compressor problem which the dealer fixed but now that everything seemingly was working fine, the car stutter at 2500 rpm and won't go over 2700 rpm. Engine light came on and the code P2646 pop up on top of that the airbag light stays on. I just got the car yesterday I can't believe that I'm already having problems with it. Please, anyone who knows what's going on, let me know, I'm really hoping that it is not anything that's going to require a lot of money to fix.

 

Does the car have any warranty if you bought it from the dealership?

The code comes up as the vtec oil pressure switch low circuit. I thought that the LX didn't have a vtec engine, so see if your engine says vtec on the valve cover.

 

I bought the car from a Nissan dealership and it has over 100K on it so no warranty.
I think the valve cover does say vtec though I can't confirm it. It's raining heavily right now so I can't go check it.
That vtec oil pressure switch low circuit you mentioned. Is it a huge problem?

 

I would check that the oil level is good on the dipstick. If you aren't sure when it was changed, you should change it and the oil filter. Also change the spark plugs if they are due. Use NGK plugs that are listed in the owner's manual.

The vtec problem can be from a clogged solenoid/screen or the pressure switch. The pressure switch is ~$40 and isn't too bad to install yourself. Cleaning the solenoid would require to remove the solenoid and I would replace the gasket that has the screens on it (~$5). It was a pain to remove on my car, but your setup is different, so I don't know how hard that would be to do.

 

2003 LX does have the i-VTEC engine. More complicated than the F-series VTEC stuff because it can do variable valve timing in addition to switching cam profiles.

P2646 = rocker-arm oil pressure switch low voltage.
This corresponds to the VTEC oil-pressure switch of the older VTEC engines.
Rocker-arm spool valve is #4 & the rocker-arm oil-pressure switch is #12. Look for bad connections.