At 08:23 AM 08/23/2002, you wrote: >IDLE 0.17% CO 135PPM HC That's at the tail pipe, right??? >Before CAT at IDLE 3.65% CO 290PPM HC. > >I have already order the new cat and will replace it >tomorrow, but was wondering what you smog pros thought >about this diagnosis.
The tail pipe reading says the cat is functioning properly, but the pre cat reading says way too rich. This will eat the cat. Get the motor running right before you spend your money on unneeded parts. If this mechanic can't verify why you're not in spec, find a better mechanic. This could be anything from poor compression to fuel pressure regulator to just dirty oil or worn plugs, or not following the proper set up procedure for timing adjustment. Make sure your mechanic has the Bentley and follows procedures. Verify mechanicals, then ignition, then fuel delivery. With a properly tuned engine, the before cat CO should be not more than 1.5%, a nice tight motor will be as low as 0.8%. See the spec on the label inside the engine hatch, 0.7-1.1% if memory serves. You want the lowest reading within the spec range that provides smooth idle. When that's in spec, the cat will purr like a good kitty with 9 lives. |
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