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I would have thought if one failed the other would too. Any help, ideas, thoughts? Thanks.

 

What RPM are you idling at?
How old is your cat and do you have any notable problems with your vehicle (including basic matenience issues)?

Just from the test results, sounds like you could be having air blockage issues or higher than normal fuel pressures.

Also, it could have been the test itself that was off, if they stuck the probe into your exhaust, for some tests on certain vehicles this is improper testing. I say this, because it wouldn't make since if nothing is wrong with you truck... and I've had to correct several mechanics (err wannabe mechanics anyways *sigh*) around here for doing this on my older vehicles...

 

HC means unburnt fuel - or hydrocarbons. It could be from a weak cat, but you passed the high idle test easily.

I'd try running a bottle or two of fuel injector cleaner in the fuel tank, and inspect your air injection equipment to make sure it is all hooked up.

Also pull your codes, you may have some error codes even with the light not on.

 

Idling at about 7-800 which I realize is kinda high. It been something I've been trying to deal with for a month or two now. I've gone through two different TPS because the voltage on mine was high at idle and I even tried to adjust the throttle plates down as for as they would adjust and it was still high. I thought maybe I bought another bad one but they all read around the same so I kinda gave up and figured ill just live with it 1-200 rpm high.

As far as the cat I have no idea. When I got it back in August the exhaust wasn't even connected and just hanging under the truck. It was rusted off at the down pipe/cat junction and just past the muffler. I have since rewelded the cat in place and replaced the old rusted muffler with a glass pack.

There is nothing wrong with the truck that I can tell, runs good. I did a complete tune up on it when I got it too.

Codes:
Codes
KOEO:
23-TPS voltage higher or lower than expected (already knew this(
24-ACT sensor out of self test range (probably due to engine not being warm)
67-AC circuit on during test or neutral safety circuit failure (foot wasn't on clutch during test)

CM:
14-2 or more successive erratic PIP pulses
32-EVP circuit intermittently failed below min voltage
96-Fuel pump secondary circuit failure
(I feel like these codes were stored before I got my hands on the truck and gave it a good tune up and all)

 

I just went through this in March. Low idle bad, high idle good. I ended up replacing my injectors after all else checked out good. Fuel pressure was correct, Iac was good, coolant temp sensor was new. I figured I had a leaking injector at idle and replaced them all. You may be able to run a fair amount of injector cleaner through it and be fine. Also, I have had good results with two bottles of HEET to one quarter tank of gas. Worked on two trucks here in the communist state of NJ.

 

Machman confirmed a suspicion I was having involving this. Higher than normal pressure can be caused by a partially plugged injector (causing a bad spray and will put in more fuel than needed, sort of correcting itself but will lead to bad emission results).

Idling sounds about right in my opinion, but if you think its too high it might be (again this -can- relate to the injectors), during higher rpms, the fuel issue would sorta correct itself. I'd have to drive the truck, but I'd almost be willing to bet that it dogs out at the high-rpm ranges.

As Lead Head said, you can try some injector/fuel system cleaners, "Sea Form" (off the shelf) seems to work really well, I would also replace the filters if they have been on for too long (running the cleaner through before and after replacing the filter, don't be greedy if you run this stuff through btw). For the more serious stuff, you can try taking the truck to ford for a diagnostic (its cheap and worth it in a lot of cases, and you can pin-point faulty parts specifically). With this you may only have to replace a few injectors, or depending on the cost of them, you could just go ahead and swap them all. This isn't really an option for a diesel though, lol...

The glass pack would make you lose compression btw, which could be a reason for high-idle also, but I bet it sounds good!

Only other thing I can think of is...well the cat, they are only good for so long, and after a few years, won't be doing much of anything.

 

Not always, with the cat(s) in place there is more than enough back pressure. I can also attest to the 'sounds good' as I have one on my '96. Let me tell you I really have to be on the throttle to hear it. It's also a bit 'buzzy' above 65mph.

 

Yeah I was surprise at how good it sounds. I just got it because it was cheap and it's really just a hunting/home depot truck so I was trying to keep the cost down. Also, I got some stuff called guarantee to pass additive. It says I you don't pass emissions you get double your money back. I figured I can't go wrong there, we shall see. Got to replace a newly broken brake line though first :-/.