Well i sure wish you would have told me that someone already to you about boost leaks and where you can get a leak check. Seemed like you had not heared of it before.Did you have it check for boost leaks?
Hello Doolittle and welcome to just answer.com, Super mechanic here. About your PT Cruiser. Let's see if we can get this concern solved.
Do you know what the fuel pressure is when the engine is bogging down?
Is there a good flow out the exhaust?
There actually is a backpressure test that can be done on the exhaust system. Most exhaust specialty shops will have the tester for it, but you might want to see how it revs with the 02 sensors, (closest to the engine) removed and if it gets a lot more power, there is a blockage in the exhaust sysem, most likely the caylitic converter.
If at all possible, see what the fuel pressure is while the engine is bogging down. There may be a loss of fuel pressure, (or flow)