OK,, here we go. Have been doing alot of TLC to my 95 f150 4x4 5.0. I get to the part where the Seafoam is enlisted. At this point and prior, no C/E light. Seafoamed the oil,,, gas tank and spray down the throttle body. All done as directions suggest. So after the treatment have been having the C/E light but not all the time. The truck runs very well for age and 215,000k . I have it narrowed down to this. When I'm running about 45-60 ish the C/E light only comes on while on an uphill grade. Top the hill and it goes off. Around here that uphill business is constant. I have replaced the EGR and its control solinoid. replaced 02 sensor, PCV valve, tried using starting fluid around some vacume lines. Then tried using the propane torch {unlit of course} around hoses and connections, No sign of leak that way. Have not smoked the vac. system yet but. Under my hood the wiring, hoses and other parts look very good no noticable rust or anything out of the ordinary. It just seems weird that the truck runs good and only gets the C/E light when it's on an uphill grade for about a minute then when that extra stress on the motor is over the light goes out .I have tried cranking down on the throttle from 45 through 75 on a down hill and flat out streach and no problem unless going up a grade/hill. I am un sure if the seafoam knocked loose some **** in the heads or what. Any new thoughts would be helpful. Guess I'm a wee bit lucky,, the truck runs just that dang ole C/E light. maybe I should just stick some ele. tape over it and move on???????????.

 

When you go up a hill does your AC cut out?

 

311 is emissions, do you still run that?

 

Just replaced the A/C comp,, accumilator and such,, last month. haven't ran it much but didn't notice anything. I'll run it today to see what happens.

 

yeah. All that system is in place and seemingly works as I said all the things I've done to track down the issue. Yeah,, 311 The Thermacter system that has 25 different things that could be wrong, Ha Ha,,just have no idea why it only flashes the light while going up hill.

 

Catalytic converter may be plugged up with all that seafoam being burned through it, plus all the deposits that left the engine.

Possible missfire, have you cleaned your plugs after running seafoam?

 

WWhite
That all happened at the same time. I looked back over the "Done List" 4-15 so right at 2 months ago. I did new plugs, wires, dist. cap, rotor button , EGR, fuel filter, and seafoam. On 4-22 i replaced the MAP sensor, PCV valve, and added a can of "Catclean" to gas. On 5-5 I replaced the EGR position sensor. The CATCLEAN had good reviews but didn't seem to make a difference with the C/E light issue. I may have used the seafoam after installing the parts on 4-15 I just can't remember the exact order. It's starting and running good no backfires but I will pull some plugs and giveum the ole once over. Is there any product or process you have used with positive results for trying to clean up the 2 CATS I have in line then straight out the back. I had been thinking about that was a possible issue maybe just partially dirtied up