98 help please?!

[ilostmiself]

Alright, ive got a 98 Gt, 5 speed. its all stock. originally from california, so it has 6 cats on it now. Im having a problem with it right now. When the car is cold it runs fine, i runs normal, no problems. But when it warms up it idles a little rough, and when under load it feels like it is missing. like it dropped a cylinder. i have no clue what is causing this. Anyone have any idea as to what it is? any help would be greatly appreciated :help2:

 

[Tally_4.6]

I would say remove and clean your plugs, replace them depending on how they look.
Then go ahead and replace the plugs wires, chances are they are the stockers and haven't been changed.
Prolly whats causing your misfire, i know when i changed mine it cured that problem right away.

 

[Jrgunn5150]

When mine developed a misfire the intake was cracked. At any rate, check your plug's first, and how many miles are on it?

 

[ilostmiself]

the car has 120k on it.. i bought it in early november, then replaced the plugs and wires within the month. it also has a new intake manifold because the one that was in it was cracked.

 

[Jrgunn5150]

So no recent changes? If not, check the fuel filter, pcv, the MAF may be dirty. I'm guessing it's just a maintenence thing.

 

[Steven]

So no recent changes? If not, check the fuel filter, pcv, the MAF may be dirty. I'm guessing it's just a maintenence thing.

thats what im thinking. If it persists.. do a compression test

 

[Mr Jones 4.6]

I would also looks at changing out the o2 sensors, just the front one. If none of that other stuff works. I would agree with the others it sounds like its just time for some maintenance .....New Plugs, Plug Wires, Fuel Filter, Air Filter, PCV Valve (also when you pull the PCV Valve clean the rubber hoses out too, just to get all the stuff out that may have been there since day one) and O2 sensors. Good Luck.

 

[white98gt]

i would check to see if iac is really dirty. on front of tb plenum. 2 bolts, 1 electrical connection, 1 rubber hose coming off it. can take carb cleaner to it. worked for me.

 

[ilostmiself]

Thanks for all the tips guys! Well over the weekend the check engine light came on. for me that was a good thing because my predator tuner is able to check trouble codes. :dancing6: After booting it up, it said that i have a cylinder 7 misfire. After i get some money, im going to try and see what exactly it is

 

[GDawg]

Definitely start with replacing old plugs with coppers and some new 9.5mm > wires. Have you cleaned your fuel injectors? Have you done a Seafoam?

O0

On Edit: Replaced plugs and wires.

Clean the Fuel injectors, replace the fuel filter. Replace PCV. Check for codes.

Thanks for all the tips guys! Well over the weekend the check engine light came on. for me that was a good thing because my predator tuner is able to check trouble codes. :dancing6: After booting it up, it said that i have a cylinder 7 misfire. After i get some money, im going to try and see what exactly it is

Check to see if your plug wire is completely seated. Check plug again. Cheap stuff first.