Mazda RX8 Check Engine Light, Lowered Gas Mileage and Exhaust Smell Issues: Potential Air Valve Problem

Hey! I had a similar issue with my '05 Mazda MX-5; they're pretty close in specs and years. I'm no car guru, but I do have a bit of experience under the hood. My car threw me the same symptoms, and it turned out the plug connection to the secondary air pump was defective. I took it to my local garage, and they were excellent; they got it sorted in a few hours and charged me just 95 Euro. So my advice would be to check your plug connections first, it might be as simple as that. If it's not, it's probably best to get a professional to look over it. By the way, could you share a bit more about the car? I'm thinking stuff like mileage, maintenance history, and such; it will help to get a clearer picture of the situation. Best of luck sorting it out!

Hey, appreciate the quick response! Good call on the secondary air pump; I'll definitely check the plug connections. In terms of car details, she's clocked about 265,363 KM, and the latest service was actually just a couple of months ago. Tried to keep her well maintained and regularly serviced. Hopefully, this issue will be sorted out without too much fuss. Thanks again for your advice!

No problem, always happy to help out a fellow Mazda owner. With the mileage and service history you provided, it's also possible that while your air valve might be acting up, it could also be a combination of aging parts wearing down. In my case, aside from the plug connection issue, my mechanic also found an old 02 sensor that was giving poor readings and was contributing to the poor gas mileage and the exhaust smell. Luckily, replacing it wasn't too costly either, set me back about 60 Euro. Remember to check your O2 sensors too when you're at the garage, those little devils can cause sneaky issues when they start to fade. Let me know how it goes, and fingers crossed it's not anything too serious or expensive for your '07 RX8. Safe roads!

Thanks for the additional advice! Definitely taking note of all you've said. I never gave O2 sensors much thought until now, but I'll be sure to get them checked out too at the garage. Really appreciate you throwing in your experiences and expertise. I'll let you know how it goes. Got my fingers crossed too! Safe roads to you as well!