I have Toyota 4runner 1996 4 cylinder. it was running good (from time to time I would lose power for 2 to 10 second than it go back to normal acceleration). I had the check engine light on for almost 8 month. last week I took the car to mechanic shop for diagnosis. the mechanic changed the spark plugs and after that the engine lost power. the car cannot go over 30 or 35 mile per hour. he changed the spark plugs and put different ones, same thing he put the old ones back same problem, he changed the wires, the fuel filter, air filter, the distributor and rotor, but still the same problem. the problem is that the check engine light is off now and there no codes. please any help will be appreciated.
It’s difficult to even guess at this without knowing what codes were present and a few other details.
It’s possible that 8 months of chronic CEL could have led to other problems.
Extreme loss of power that is intermittent in nature would point me to:
A severe engine miss; crank sensor, coil breakdown, or an intermittent fuel pump.
Sounds like some bad guessing as been going on because fuel/air filters and rotors will not cause an intermittent problem except under the most freakish of circumstances.
"I had the check engine light on for almost 8 month"
Has anyone ever read the fault codes?