I started out with a low mpg problem soI replaced the plugs 3.3 has 88,568 miles.
Replaced plugs with Bosch Platinum +2 and the MPG became worse?
I now have a surging or fish bite problem while at constant trottle?
Is it the plugs or someting else?

 

TTT Thanks!

 

good god.. take out the bosh and throw them as far as you can.. you picked the WORST plugs out on the market.. might as well put 2 stroke plugs in it

 

I was looking for a reason why they are the worst, and what would be the best plug to replace them with?
I have used them in honda's with great results and maybe need to start putting them in my chainsaw!
I have noticed that the surging gets worse when the A/C is on?

 

I also have a 2005 Caravan with the 3.3 V-6.

It "surges" between 35-50 MPH under light throttle when "cold". No problem coasting or accelerating.

Starts fine and the surging either goes away or is much less after being fully warmed and also seems to be gone when the A/C is working oor if I manual select D (3rd).

Seems like it is running very lean during the cold/warm-up period. Does not appear to be a mis-fire or a TCC issue. No CEL/MIL.

Did Chrysler get the mapping wrong?

Thoughts and ideas?

Thanks