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04 Ford Expedition Emissions Problem

I have a 04 Ford Expedition. Recently, I had emission problems. The car would unexpectedly jerk while driving. The “check engine” light came on. I replaced the catalytic converters. The “check engine” light is no longer on. However, the car is still jerking while driving. It feels like hitting a speed bump: a short “thump-thump” and loss of power, then it drives normally again. Any ideas? Does this sound like the O2 sensors are going out?

Did you read the error code(s) what were they? The answer may be there.

It sounds like a transmission problem to me. Has the transmission fluid been checked? How many miles on your Ford? Has the transmission fluid been replaced?

Sorry for the delay in responding. Out on a business trip.

I haven’t checked the error codes. Is that something a consumer can do or do I need to take the car into a shop?

The transmission has been regularly serviced. The Ford has 130,000 miles on it. The transmission fluid was changed at 120,000 miles.

Only at 120K? yikes!

Take it to an autozone near you, they can read any codes for free (past codes are stored). It sounds like a non-emissions problem now, which may have caused the emissions issue earlier. You solved an effect, but not the cause.