So, new to the forums, fairly new to working/maintaining my own vehicle. I'm not very mechanically inclined, but do have a few friends that I can use as resources for a few things. These forums have become a great help as i've managed to find a fix for my Door Ajar problems, and less easily the fix for my windshield wipers going on and off randomly.

What I am needing though is a little bit of advice. My truck is a 1999-f150 Lariat. As far as the records I have everything is stock (gears, what not). What I am looking for is advice on a problem, and then some general advice to look for in the next coming miles. My truck just reached 115,000 and looking to try and keep it running as long as possible. It just had a tune up and wires and plugs changed.

What I get randomly after the plugs being changed(and why i brought it in in the first place) is that randomly i get a misfire causing a service engine soon light. I've checked the plugs and one time one of them was loose so I had it taken back to where they put them in and had them check the wires again. They ran the codes a second time and said that it could also be due to build up on the catalytic converter(I believe this is what he was saying), and that may need to be replaced. What im not looking forward to is the $1700 dollar estimate I got after finding out there is 4 cats on my truck. As im not mechanically inclined whatsoever theres no change of me doing this myself. While recruiting a friend to help me may be an option im looking at options other than replacing the 4 cats. I've read up that you can replace the 4 with 2 high flow but this causes increased noise? Im just needing options and possibly anything else it could be. I dont want to take it into have the cats replaced to find out its not actually them.

Also, any info or ideas on what I should be looking for at 115,000 miles? Is there anything worth still putting on my truck to increase performance? Any information is helpful.

Im currently at work, so if you have any questions I should be able to get to them quickly. Thank you in advance for any help.

 

well with that kinda milage you probably ana start being nice to your truck if u dont want to wear it out, tranny seals are probably drying out, clutches are probably thin, so you probably dont want to up your horsepower, but t wot hurt to free up some, the first thing maybe you should consider is converting to a electric fan, that free's up to 20 hp, you will probably need to rebuild your engine, especially the berrings. as for the cat situation do u have strict emission laws there? if so yeah you will need to buy some new cat's of go to the wrekers and pick up the whole cat section for 300ish canadian so that like what 50 bucks american lol, if you dont have the strict emission laws you can do what i did just cut them all out and put o2 simmulators on the rear sensors and for the added backpressure i just pu a resonator that i found on the floor of a muffler shop in, and it's as quiet as it was before, just a lil stinkier lol,

 

i am assuming you have a 4.6? due to the fact that you stated plugs and wires changed

did you change your trans filter and fluid? I would definantly go for 2 highflow cats VS 4 new or used stockers, yes you will get a bit more noise but it you or still on the factory muffler than you probably won't notice it in exhaust noise.

you didn't state what you use the truck for or how you drive


I'd add a gotts intake and baby the truck...

 

where did that come from? the original poster didnt say he's having engine problems, did he?

i bought my truck with 88k almost 3 years ago. now i have 119k. i replaced the plugs, flushed the fluids, replaced one coil, and change the oil. to the OP, just keep up your general maintenance. if you cant do repairs on your own, bring it to someone you can really trust.

 

Its my all around use vehicle. During the week its mainly just to and from work. But on occasion I do take it down to see my parents or on a small trip. Usually within 4-5 hours drive time.

As for the trans filter and fluid im not sure. The tune I had done may have included that but I didn't get a itemized list of what they did. On the 2 high flow cats what should i be looking for price wise? I'd probly take it to a shop here locally and have it done. If its not to terribly bad I may have my exhaust looked at and maybe go with dual.

What im looking at is best bang for the buck. I want to put money into what counts and not spend money on things that in the end will not help or even hurt the truck. Thank you all for your help so far!