I have a 99 ranger 4 cylinder that is still missing on idle and it could be missing on higher rev I just can't hear or feel it. after I've changed the plugs and wires, tested the coil packs and even got a new filter cuz old was dirty lol. I do have a check engine code for the emissions system but I'm yet to find out what's wrong with it without spending a bunch of money for each part. Idk if I even called it the right thing it's been awhile since I plugged the reader into but it's the coal canister and all that jazz. I was thinking about replacing the breather hose that runs next to the filler hose but I need a day off for that. Any suggestions to what it could be. My stepdad thinks that it could be the timing but we haven't messed with that so I don't see how it would be off

E: on a side note my gas mileage dropped like 2-4mpg consistently but I'm debating whether that was because of the winter fuel tht Ohio uses?

This post was edited by YourHopeAnDream on May 5 2015 09:00am

I doubt it is the evap system but it is a possibility. That is what your codes are for. It sounds like it might be time for an O2 sensor or catalytic converter.

Wouldn't the O2 throw a code? And a plugged cat would smell right?

When it fails completely it will. It could be switching slowly and not throw a code. A scan tool with live data will tell you what is going on if you know what to look for.

Alright so I may just replace the O2 Bc the truck does have 170k miles on it and we haven't done it with the 70k miles that we put on the truck lol so who knows if it's ever been done. I just did the spark plugs and they still had motor craft plugs in them sooo my guess is it's original O2 also. I'll lyk how it goes once I get around to it

I replaced both o2's. How long till I will be able to tell if it worked? Or should it be close to instant? I don't hear a miss now but I'm not sure if it's like the placebo effect.

1 or 2 drive cycles should build your fuel trims back.

By drive cycles you mean me actually driving the truck on my commute or is that about the number of gas tanks that I'll run through

A drive cycle is cold to closed loop operation so 5-10 min of driving. After a couple warm ups/drives it will be calibrated.

Ok well it has been through 2 of them just now got done with the second so tmr I should start seeing improvements if they haven't already. And if it still misses what would be the next order of action? Should I try to replace some of the easy evap system parts like the breather hose for the gas tank?