Hello fellow Mazda 3 enthusiasts.
A little background (TMI):
Couple other things I'm concerned about: intake build up and pre-cat health. For the intake, thinking I'll try Seafoam, and I wanna measure the back pressure to see how the cat health is. Ideally the PCM update resolves my problem though...
Anyone ever remove their pre-cat? Was thinking having a shop literally cut it out and put in a straight pipe (province doesn't care about emissions), my concerns would be about the downstream O2 sensor and whether or not it would care.
Also the throttle body noise?? Like a humming sound, cleaning it was a little annoying with it whining away. Also makes the sound when the engine turns off. Worth replacing? Read it is somewhat expected behaviour.
Thanks in advance!
Reggae
A little background (TMI):
- Few months ago my wife said the car felt slow, hard to pass other cars.
- Got a P013A fault code. Stupidly threw a new part at it thinking that would fix it. The downstream sensor was welded in there pretty good, so I bought the part but gave up and let a mechanic throw it in for me.
- Replaced tires (weather worn, cracked).
- Took a long 9 hour trip.
- On the way home, the check engine and traction control lights started flashing due to a misfire (P0304). I determined that the cylinder 4 ignition coil was shot. I did this by moving the coil, and the problem followed it. Of course it was Labour Day and NAPA was closed bahh. Of note there is a TSB for newer MZ3 (01-014/16), and funnily enough the diagnostic procedure is the same thing I did.
- Replaced coil.
- Got home, felt fine the whole way.
- Weeks later I got a P0140 code. But strangely the sensor was outputting a signal (verified with Torque).
- Replaced all ignition coils, all spark plugs, cleaned MAF and cleaned throttle body.
- P013A came back.
- Now I've done some digging, and turns out there is a TSB for this issue!!!! 01-004/14 says to upgrade the PCM to 88.04. Previous owner had the car in for TSB 01-019/13 (headlight flicker) which updated the PCM to 85.04, so I'm expecting mine is missing the 88.04 update.
Couple other things I'm concerned about: intake build up and pre-cat health. For the intake, thinking I'll try Seafoam, and I wanna measure the back pressure to see how the cat health is. Ideally the PCM update resolves my problem though...
Anyone ever remove their pre-cat? Was thinking having a shop literally cut it out and put in a straight pipe (province doesn't care about emissions), my concerns would be about the downstream O2 sensor and whether or not it would care.
Also the throttle body noise?? Like a humming sound, cleaning it was a little annoying with it whining away. Also makes the sound when the engine turns off. Worth replacing? Read it is somewhat expected behaviour.
Thanks in advance!
Reggae
