4.0L 184,000 mi
Driving home on highway, suddenly had problem maintaining speed. Got off exit. Seemed to idol OK, but stepping on gas only wanted to go very slow (some rattling sounding like heat shield?). Got it home and replaced the fuel filter (rented fuel pressure gage mistakingly showed no pressure at first) but fuel pump working. Same problem. No codes.
I believe timing chain had been getting noisy (been reading lots about that - happens around 2400 rpm and quiets after oil change).
Question. Could the chain have jumped a tooth? Would the symptoms be as discribed? Any other possibilities?
Of course holiday weekend here, thinking of towing to dealer, but value the opinions of the Forum!
Thanks. Happy New Year!

 

Check the exhaust for excessive back pressure.... Philip

 

What's the best way? Are you thinking blocked cat?

 

At the moment, with no tests, yes!... Remove the upstream O2 sensor.

Does the engine now rev freely??

 

Thanks Aquanaut20.
First, following my Haynes manual, I connected a vacuum gage to the intake and saw it drop and slowly recover after revving several times. Next, removed right side upstream O2 sensor and repeated the vacuum test. No drop, just retruned to idol level. Took it out for a ride around the block and it was definately (maybe not perfect) much more powerful than the other night. So I'm looking into replacing with a direct fit cat - any knowledge about Eastern brand (about 100 cheaper than Walker)?

 

You now need to find the reason for the collapse.. Over fueling is the most common cause.

If you don't fix that first the new CAT will suffer a similar fate... Philip

 

I guess I will have to get it hooked up to an analyzer to see if something shows. Has been running fine, no codes and just passed emissions. Could it have just failed at 184,000 miles?