: Engine bogging bad....help

07-05-10, 02:41 PM
2 months ago I installed a monster clutch and lightweight flywheel. Shortly after the check engine light came on but car ran fine, so I never got around to having it scanned "figured it was 02 sensor or something minor".

Now the other day the engine started running rough and bogging under throttle. Will cruise ok but as soon as you apply throttle its like the motor is choking...

Had it scanned and they said it thru catalytic deficiency and random misfire codes.

Could clogged cats really cause the motor to bog like this?

How do I fix this?

07-05-10, 07:44 PM
Do you have the actual code numbers? Without knowing the mileage on the car, it is hard to say, but bad catalytic converters is not the most likely problem. Defective, misconnected, or badly grounded O2 sensor is more likely, but there are many other possibilities.

07-05-10, 07:47 PM
Join the club.:banghead:

I have a check engine light but no bogging (YET!) :hide:

I can get it to almost go out at a certain RPM in 2nd. :banghead:

I am gonna try to have some data logs run.

I show a misfire code, but the car runs great at the moment.

Onstar keeps sending me email about the condition.

07-05-10, 08:16 PM
Mileage is higher at 95K. Didn't get the actual codes...

As said the engine light came on very soon after the clutch install, but the car ran fine for a few months.

If it was an o2 sensor could it really take that long to affect how it runs?

I didn't think an o2 sensor could have that drastic of an affect on how the car ran, thought they were simply emissions...

07-05-10, 08:42 PM
The front o2 sensors help control fueling, the rears are for emissions

07-05-10, 08:42 PM
Perhaps some of the tuners here can give more detailed information, but as I understand it the computer uses signals from the O2 sensors, among other things, to adjust fuel mixture.

07-05-10, 08:56 PM
Generally when there is a suspected O2 problem, and the drivability concern does not go away at WOT, then it's less likely to be an O2 sensor. Data logging would, of course, prove that.

Usually the fuel trim range does not span enough for the engine to misfire, but a persistent misfire will almost certain eventually lead to a insufficient catalyst code, as the unburned fuel can temporarily cause the cat to not do its thing. Over time, permanent damage is possible. Hence the code.

O2s are very much needed for emissions, fuel economy AND drivability.