i think im running rich

so how do i fix this? just put in new plugs and getting new wires to help with my bad gas mileage.

Running rich can be the result of a "false" lean condition, where the O2 sensors are telling the PCM the mixture is lean, when it really isn't. Causes can include misfires, exhaust leaks before the O2 sensors, or faulty O2 sensors. A false lean will usually show up in the form of elevated long term fuel corrections (BLM's). Scan software would help you track this down.

im not throwing any codes for the o2 sensors. this good tuning place said they can check all my computer reading for about 90 bucks. do you think it would be worth the money to have them do that.

You could buy software, and datalog the PCM yourself. Might cost more initially, but then you would have something you could use whenever you want to see how your engine is running.

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