jiminem2

Got an 04 XLT 5.4 Triton 165k

Began to notice some sort of hiccup between 45-50mph - only if gas was let off and came back into it. After some time, it began to hiccup going up hill as well at these speeds. Towing a load, it is more prone to do this. I originally thought it may have been the transmission jumping, because it would not do it with OD off, now it doesn't matter if it's off or on.... Took it to Advance Auto b/c check engine light stays on -and they said it was a Cat Code. Hard to describe the hiccup, but it reminds me of when I had a bad distributor cap on my S10, and the engine would jump. If I tow my boat uphill, the check engine lights start blinking, the hiccup is so bad, I won't tow my boat anywhere uphill bc of powerloss and engine hiccups.

I also have a small manifold leak, I believe.. kind of have that diesel tick.

connorfx4

A flashing CEL indicates a misfire. When was the last tune up done?

jiminem2

Couldnt tell ya, only had an oil change. Brought the truck in May.... It only flashes when I dog it up hill. 99% of the time it just stays on without blinking. From reading other posts, I have heard a bad cat can cause misfire?

As of now, only reason I'm thinking its a cat is because of the one and only cat code. Now that it has been flashing it may be throwing a misfire code I supposed. I'll bang on the cats and see if I can hear some rattling tonight.

chayes627

If you don't know when and if the plugs have been changed, that would be first. Motorcraft or autolite plugs and new coil boots and springs. A bad misfire having raw fuel go thru the exhaust can set a cat code.

Martian

Good way to kill an oxygen sensor, too.

connorfx4

Start with a tune up. I would stick with motorcraft plugs. Let us know how it is after that. Good luck

jiminem2

Turns out the truck shortly through another code after the cat code. Mass airflow sensor. I took it out and cleaned it. The misfire is much more faint. Probably need a new one all together, fella live on a dirt road so it's prob chalked up good where I cannot see. Hope this helps someone out.

techrep

iTrader: (1)

165k miles and you do not know when the last plug change was ... Dude, change your plugs.. a flashing CEL tells you this... while your under the hood.. pull your TB and clean it and your MAF.. change your fuel filter.. give it some love !!

jiminem2

**** it wasn't the mass air filter. It must have tweaked the system for a couple hours. Got a p0174 and p0420 code. All the grease monkeys at part stores have a diff option. AutoZone recommends a maf for these two codes. Not what I needed. All I know is an 02 sensor couldn't cause this right? I understand an 02 can go bad from a misfire though.

Dripper

you and i are in the same boat.p0420 code came up at autozone.i made a new thread for this problem.have yet to figure it out.

below is a picture i took yest from autozone.this may help you out,"may".

thing is,if it's a misfire would the truck limp,jump or hiccup along the way? mine doesnt.no whsitling sounds im aware of so no vacuum leak.i pray to god almighty it isnt no#3 oil leak in pistons from manifold gasket.

keep your post and fixes updated.ill check back.your help/ideas may help me out,vice-versa.