Future expensive fix or cheap fix?

[jonny138]

I just got a tuneup like 3 weeks ago and everything was cool but now it seems that when my engine is warm the car likes to sputter, it goes away when i excel but when i've been driving for like 20 minutes or more at a consistent speed it will cough or sputter a little. i read somewhere that it may be "running rich", what does that mean, anything i can tell my mechanic to look for when i take it in? my engines heater gauge never goes very far above the bottom line, my heat isn't all that great. . .i think that's about as best as i can describe it.

my engine has been idling a little louder than usual, sometimes a few funny noises but it seems to still be doing fine. is this something i should get on right away or not too big a deal? thanks to anyone that can give me some info on this stuff!

[Zanzer]

Running rich means there's too much fuel in the air/fuel mixture. Sounds like the car is running cold. A cold engine will run richer. Maybe time for a thermostat. Sounds like yours may be a little lazy or wrong heat range(?).

[lessersivad]

I agree about the stat. Make sure to get a Ford or Mazda stat. There's a sticky about it in the repair help section.

[jonny138]

thanks a lot, i love this forum!

oh real quick, i looked for the thermostat sticky but couldn't find it, link anyone?

[FestYboy]

here: http://www.fordfestiva.com/forums/showthread.php?t=6901
make sure you burp the system as well...get all the air out.
another recomendation would be a new DENSO o2 sensor...