help

[mazda03maniac]

i don't know whats wrong with my car. it idles at about 500 rpms. and in 3rd, 4th, and 5th the car feels like it dies when i get up around 5000. Do any of you know what this could be. the check engine light comes on for a while, turns off for a while, and then comes back on. and everyday i try to get it looked at. the CEL turns off before i get there.

[jdm4lyf9]

maybe bad 02 sensor or something.

[mymp5]

no idea thats weird so it keeps fixing itself if it keeps shuting off

[peajay]

that could be so many things.....air metering issue, evap/emissions issue, fuel delivery issue...I'd say take it to a dealer and see if they can catch the code and then go from there.
fyi: to catch a code once the light comes on DO NOT TURN THE CAR OFF, im not saying you will catch it this way, ive had cars with cels i cant catch, but its still a must to at least make an attempt.

[msp35]

The dealer can still find what codes have been thrown recently....autozone
may be able to do so as well.

[Alejo_NIN]

i'll go with a manifold crack/1st O2 sensor bad.

i had the same thing happen to me, it was a crakc in the manifold :(

[orng1]

The ECU will store the codes if your gettig a CEL even if the light goes off on its own. I vote actuator though, I had poor idle and couldn't make boost Although a lot of you have had it go the other way where it wont control the boost and had too much, mine made no boost when it went bad.

[Witchdoktor]

any recent mods done?

and like others said, get the cel checked. light or no light it's probably stored in the ecu.

[DiscreetSpeed]

wrd cel checked...id make sure everything is well connected.
ie...MAF sensor and o2 sensor.

[mazda03maniac]

well advanced auto says it a 02 sensor but last time they said that it ended up being something totally different. my mechanic said we will hook his snap on computer up to it and take a ten mile drive and he said that should tell me anything that is wrong with it.

[Witchdoktor]

cel # ?

[crackerjakx]

I've been having an issue with not being able to build boost unless I TRY to. And on my vac gauge when I'm cruising at 45 in 4th the needle jumps back and forth (in 4hg increments) about every 5 seconds kinda intermittently. My idle is very slightly lower than 750 and my vacuum reads a steady 21-22 @ idle (or like 18 with the a/c on). I haven't had any CEL at all. Could this be an 02 sensor? Timing? or just a plain leak?

[mazda03maniac]

i don't know why but all of a sudden my problem stopped. now it works fine again after a month or two. when i was on my way to my mechanic to look at it i wanted to make sure it was doing it still and it is not. crazy car