POWERLESS when cold
 

I know most small engines are, but it has gotten worse lately. The thing strains hard when cold and even after the guage shows normal op temp, it takes a good 20min before power returns to normal. I'd swear it gets back to normal faster if I happen to turn it off (like after a short trip) then back on only 10min after cold startup. This is all much more drastic lately. The truck is in perfect tune and has new plugs/cap/rotor. Almost feels like the valve near the MAF that stays shut for warmup is sticking closed after its up to temp (???) mileage has gone to shhh too

Mine would do that, seems to have gotten better since I replaced the O2 sensor. I had a CEL, but was too lazy to read the code...

I have never had a CEL

catalytic converter?

No power when cold
 

I am having the same problem rigth now. If I let it run for 5-10 minutes, it is fine. But if I just jump in, start it and go, a snail would out run me.

The check engine light is on, I just need to pull the code. Any thoughts??

Pull the code and look it up:
http://personal.utulsa.edu/~nathan-b...85diagnosi.pdf

I always warm my engine up for a minimum of 10 minutes before I go anywhere when it's cold. Summer I go 5 minutes. Old habits from the Hummin Cummins days.