I've read through a number of threads here over time talking about this same issue. When cold, power loss when accelerating above 2,000/2,500 RPM. Seems to go away when warmed up.

My rig has 167,000 miles on it. Plugs, rotor, cap, wires, timing belt/H2O pump, upper oxygen sensor done about 30,000 miles ago. Compression test done a couple years ago, still decent. However, it's been hesitating for years (since at least 2011), but seems worse when it's cold outside (today was in the 30s, and I really noticed it), and seems to be pretty bad now.

I recently fixed my CEL regarding my EGR valve (blocked passageways), so I don't think it's that. I did run a CEL for about 4,000 miles. Could that have fouled the plugs or O2 sensor?

I seem to have taken a bit of a hit in mileage, too. Even with bumper, winch, roof rack, 235 mud terrains, I used to get 22/23 MPG. Now it's more like 19 or 20.

Any other suggestions? Test ECT?

I would start with wet & dry compression tests...

I did a compression test, but I think it was a few years back. Numbers were fine for a rig with 145,000 on the clock. Time flies, though.

You mentioned it, do another one.

Compression numbers are lower on a cold engine than on a hot one, pistons expand, rings seal better - your symptoms are those of a worn engine, and at 167,000 miles, that might be your problem.

You mentioned it, do another one.

Compression numbers are lower on a cold engine than on a hot one, pistons expand, rings seal better - your symptoms are those of a worn engine, and at 167,000 miles, that might be your problem.

10-4.

Well, I just had the transmission rebuilt. Hope the engine isn't next! Oh well, it's just money. [emoji1]

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Install a 2.3 liter engine in it like Eric just did on his sport.   That would turn your two-door into a beast.

Install a 2.3 liter engine in it like Eric just did on his sport.   That would turn your two-door into a beat.

Yeah, that'd be pretty sweet.