Hey everyone,
so recently I had my truck throw a code for a misfire on cylinder 5 as well as loss of power on the freeway so I did some diagnosing and took care of most things that would cause it. Spark plugs were relatively changed a year ago and I checked them and they still looked good so I just changed out the wires, distributor cap and rotor, ignition coil. Still experienced the issue of loss power and difficulty accelerating uphill. Took it to the shop and the guy couldn't get much as it only misfires when under load so we had to guess and check. Ended up replacing distributor and changed spark plugs to champion ones as he said it might've been due to the current plugs being autolite. Issue was still there but now it would say other cylinders were misfiring. Had my dad take a look and he thinks it has to do with the catalytic converter being clogged but I haven't gotten any codes regarding it. I'd like to try and take care of the cat or to see if it might be due to possible intake manifold gasket? If anyone has solutions or ideas on how to take care of this please reply to the thread , anything helps!

Dad already talking about possibly getting me a car but don't want to let the truck go just like that

 

There are two free tests you can try. One being checking the plug wires to make sure they aren't crossing one another(and if they are at a 90° angle). Another one is remove the O2 sensor in front of the cat and see if it runs better.

 

Okay yeah I'll definitely give that a try with the o2 sensor. And with the wires I'll fix em up because when I did them I did it correctly with the placement but after I got the truck back from the shop that did my distributor, the wires weren't put on the distributor cap the way I had them, way sloppy so I'll definitely give those a look.

 

There is a technical service bulletin in the FAQ/DIY section that regards plug wire routing.

I agree with the others though, check the cat first, and also take a look down in the throttle body, and see if there is oil pooling down there.

 

It sounds like you have a fuel pressure issue more than anything my 5.9 does the same thing it'll idle fine and go down straight and flat roads but once at a incline the fuel pump looses pressure causing multiple misfires

 

You may want to look at the date of the posts, Julyerick hasn't been here since then.