[Naytoo]

Hello, my names Tyler.. I've been having a few troubles with my 99 Gt. It has th 4.6L Sohc.

Basically, I took my car to a shop of a friend... He didn't have my particular fuel filter and installed a different one... However that isn't the worst f my problems... I originally changed it because Ever now and again it would run a little rough, just barely though.
Previously I had a bad idle, which was corrected after tuning the throttle body a little. Also the car would SOMETIMES die when I put it in neutral and was slowing from speeds above 50. ( Usually don't use neutral though. )
Some time after changing the filter All my problems got worse... One day my car was running like crap and I lost all power.. Basically it died and when I restarted it things were running smooth again.. A few days later the problem started again. A few days after that it got so bad the car wouldn't run anymore. At this point in time I didn't have the funds to work on it...
At any rate I went to the dealer and bought it a NEW IAC Valve yesterday the 20th. And after installing it I reset the computer. Took 2 tries and it started up. I had a friend ride with me to the gas station... Along the way it died on me again but started right back up. I noticed that when I would get on it it would have Problems. ( I am assuming due to fuel filter. ) I purchased a new fuel filter but have yet to install it. I had wiggled the old fuel filter and started it up... It drove great for a while, no problems at all... This morning I went out and started it up! It was running like a champ.. Again more troubles! 3 miles down the road my check engine light came on... I quickly pulled into schucks and used the obd 2 scan tool they had... At which time it told me " Running Rich in Bank 1 ." Which to me means Bad oxygen sensor or Leaky Fuel injector... However I was curious if the fuel filter would have something to do with that as well.... Please help me figure it out... I don't have a ton of money to try and fix Every tiny thing in assumption that it'll be the problem... Any advice or other would be very helpful!!

[trueblue01]

Had the same problem and it ended up being the mass air sensor

[1FUN4RD]

I dont know but it doesnt sound like the fuel filter is the problem

[1FUN4RD]

If it was me I would seafoam it!!

[Naytoo]

Mass air flow hu... Okay well I am going to wait an hear a few more responses, thank you though !!