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Topic Review (Newest First)
02-12-2011 05:26 PM
bc3_Jeep I was gonna suggest that......but you beat me to it..... )
02-12-2011 04:28 PM
Problem Solved

Fixed! Problem was the Catalytic Converter.
The guy at the muffler shop said it was good that I didn't push the engine too hard or long as the result of that is a blown head gasket from the high back pressure and temperature.

02-12-2011 01:17 PM
Power loss above 1/2 throttle, code 51

My 1995 2.5L YJ (165,000 miles) suddenly lost power above 1/2 throttle.
While climbing a hill the exhaust note changed (got deeper with a sound like a turbo bearing failing) and after about 2 minutes the check engine light came on and stayed on until the engine was shut down.

I noticed that there was also a loud exhaust rattle at idle and above half throttle there is a whistling/turbo bearing noise (the engine in non-turbo) after this started.

Engine codes were set and they are:
12 - (Battery had been disconnected)
33 - (A/C clutch - no A/C on this vehicle)
51 - (running lean)
55 - (end of diagnostics)

I've replaced the Fuel Filter.
Fuel Pressure is 35 psi running; 37 psi key on, engine off.

Power is OK up to about 2,500 RPM or 1/2 throttle. Above this there is rapid power loss . When throttle is let up to under 1/2 power is restored if the RPM is under 2,500

Any suggestions as to the problem?

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