All of a sudden the engine only loses power(seems to run on 2-3 cylinders) when it it under load otherwise it seems to run ok.

I still have the original fuel pump (I'm hoping it ain't that cause it looks like you have to drop the tank to replace it).
I had a complete tune up 5k miles ago, new filters, plugs ect.

What fuel pressure testor would anybody suggest? Actron CP7838?

Maybe the PCV valve is clogged?


Thanks

 

Start with the spark plugs and wires and distributor rotor.

 

I forgot to mention, I replaced the cat about 2 months ago with a magna flow to get it to pass smog. The car actually ran better with the new cat.

 

When was the last time you replaced the fuel filter?