I found out my 99 f250 does not have a catalytic converter. And I still cat fix the idling problems its haveing. The muffler shop told me I don't need it but just trying to make sure that I don't and if it would cause my idling issue.

 

Look under your hood for the emissions sticker. It will say if your truck originally had a catalytic converter. It will look like this:



As for an idle problem, have you inspected/cleaned/replaced your IAC?

 

Yea I changed that. And it did have one on it.

 

No, that will not cause an issue idling.

 

what kind of idle problem are you having? my 2004 5.4 drops when i first start it and then jumps up to 1000rpm and then slowly idles down to 750RPM. i replaced the IAC, TPS, new plugs and boots, fuel filters and even replaced the fuel pump.

 

The only thing I haven changed is the tps. I'm bringing it to ford I'm tired of it. I just bought it from my friends dad and he had all kinds of stuff change and a lot of it was from ford so I'm going to get all his recipts an go over there with it cause it was running good. But went to the camp a few weeks ago and now it's running like crap

 

Mine will idel high then idel real low and kill. Some times it will get up to 2000 rpms and just stay there. Then I got to kill it cause I don't want to put it in gear like that. so it's acting real crazy and never has a check engine light just random codes that are allways different.

 

I know the PCM,fuel pump,some injectors,iac,coils and ox sensors were changed on it. So it could be someting that was already changed. Who knows it's just got me to that point where I don't want to do it anymore I work on stuff all day so last thing I want is to mess with this truck on my days off...