car engine problem

[06BUSA]

A bad O2 sensor can do that. O2 sensor can be the root cause of plugging a cat converter. All the excess fuel buring in the converter, cokes it up. Check the plugs to see if one bank was running rich.

the cat actually melts down..  

An 02 sensor can cause this but exhaust leaks (between engine and cat) can do this as well. It allows excess oxygen into the exhaust and the cat works "too" well. Bad wires are also a big problem (excess fuel in cat)

plugged cats tend to affect all cylinders anyway and not 1 or 2 as in a miss

I dont see excess oxygen getting into the exhaust system. The exhaust would have to be pulling a vacuum.
If you suspect the converter. Beat the hell out off it. Preferable after removal dump the crust & crap you loosen and put it back on. That's a quick/temp fix if its a plugged converter.

[WWJD]

So did you have a chance to take a look?
Any updates?

Wimp out and drop it with the Mechanic?

hahaha missed my op last night. maybe tonight. I have another car to use, so I'm not hurting. doubt I'll be able to get to the fuel filter, but could very well be that. I may replace the plugs with new, since they are right on top, and buy some new cool looking cables, just incase, and add to the bling factor

[ibified]

WWJD: if I remember correctly, the fuel filter on the Miata is in the engine bay, and they aren't that hard to get to. I'm thinking it's right there on the firewall.

Best of luck getting it fixed - any chance you could call the race shop that built the motor and ask them for ideas? they're probably a lot more familiar than yu are with that particular motor.

[SnapAttack]

Not familiar with Miata's but here it goes:

Fuel/Air/Spark/Compression needed to run the engine.
No codes so doubt it's a sensor.

Fuel - Run a can of Seafoam (1 bottle to 1/4 tank of fuel) to clean injectors. Replace fuel filter. Check TPS. Could be secondary injectors (if equipped) if hesitates under acceleration.

Air - Check filter. Check the air flow Door/fuel door assbly in the intake.

Spark - Mentioned above.

Compression - Check cylinder compression. May have ring leakage.

GL