Hey everybody, I've been reading this site for a while, lots of great insight here. I'll just give a little background on my situation.

I bought my 2005 Mazda Rx8 in April of 2013, so I've had it for about a year and a half. In December, the car wouldn't start, and I took it to the Mazda dealership and they said it had low compression and I needed a new engine.

Not giving up on the car, I did some research and in January I changed the ignition coils and spark plugs. Car started back up like new, worked great until June, when I started to get a flashing Check Engine Light and the car accelerates slowly now. I realized today that I did not reconnect the intake valve (the tube with the green and white ball on it) back, so it looks like I've been driving with a vacuum leak for the last 6 months. I reconnected the intake valve today but the problem is still here.

The car is running rich, I'm getting barely 9 MPG now. The CEL will alternate between flashing when I am accelerating and just on when I'm driving a constant speed.

I changed the spark plug wires today, since I didn't change them back in January, and no luck. Then I bought some MAF cleaner and tried cleaning the MAF; it did not fix the problem.


I don't know what else to check. What kind of damage does a disconnected intake valve for 6 months do to the car? Does it affect the CAT? Is the car finally succumbing to the low compression in the engine?

Any help is greatly appreciated.

 

Plugs, wires and coils are maintenance item that needs to be replaced all together every 30k.

I've read on here, that its not a good idea to drive your car with the CEL, have the codes read and post the codes.

Meanwhile, replace the coils, since you just replaced the plugs and wires. Clean the MAF sensor, clean the ESS sensor. then perform the 20 brake stomp reset. Start the car let it idle and let it learn the fuel trims. If it appears to be dying, then crank your AC to max.

While you are at it, inspect your air filter, clean the throttle body, ensure all the hoses are connected to the intake accordion tube ..

As far as compression is concerned, only a compression test can determine the true engine health. Other than that, hot start issues are a critical indicator of low compression.

Have the codes pulled asap though.

 

^is on track with the coils but your mpg could suggest failed CAT due to your misfire if this is the case and your engine isn't dead or dieing because of a clogged CAT it soon will. Driving with a misfire on a rx8 is not a good thing to do. Check your CAT ASAP. The check valve you failed to reconnect if it's to the shutter valve on the in take I think your safe there other than crapy idle. Get those coils changed and do all the above poster said and check your CAT. If it continues get comprssion test.