When I accelerate, at 2500 RPM the car feels like about died but never died. It happens for just a second, like it slowed down then accelerate again. It happens in every gear around 2500 RPM. I am wondering what is going on. The car is running fine. Lately, everytime I stay at redlight, the idle RPM is right at 750, which is good, but at times it drops by 50 or goes up to 1000 without me pushing clutch or gas pedal. Can ya’ll help me understand what could be the problem. Oh ya, last week, the exhaust was rusting and everything inside was rusting and since then I changed the whole rear muffler section together with my sparkplugs. It is all OEM parts. Then my gas mileage drops from 28 mpg to 23 mgp. CAn ya’ll also help me on this. Thanks a bunch!
possibly the O2 sensor.