I have a problem with the car bogging down while trying to climb a hill, other than that it runs decent on flat ground. It ran fine until I took the "violin case" off this weekend, I was going to put a tube in place of it but didnt get around to getting it done and had to come to work, so I put the violin case back on. I also disconnected the battery and had the check engine light on before for some egr crap but it ran fine. I pulled in to work and the light came back on. I checked all the hose clamps on the air intake. I was thinking maybe where the violin case hooks to throttle body there might be an air leak since there isnt an adjustable clamp right there and the rubber coupling is over 20 years old.