Several problems S5, o2
 

Hello

I had many problems with my car, it has bad mileage, the idle drop very bad when the car is warmed up, i feel the car is not running properly (full power) when i reset the ecu it goes good till the error comes again.

I will change the O2 for sure.

When i checked my car it appear 17, 30, 33 and 38 error codes!
After that I realized I have no Air control valve

http://cgi.ebay.com/ebaymotors/Mazda...Q5fAccessories

I looked that error 30 and 33 are realted with air control valve.

Now, I need some advice, what should I do??
Get and install an air control valve or keep like this?
Change O2 sensor?

Writte any problem you think It will affect.

I would be very greatfull if you help me with this since Im from Peru and Its not easy to get good advices around (ppl who knows about rotary engines)

Thanks

You don't need an ACV or the associated solenoids, unless you have to emissions test your car. I'm guessing you don't.

Code 38 is the AWS (Accelerated Warmup System) solenoid, which is useless anyway.

Code 17 is the 02 sensor, which means it's either not connected, or the ECU is not seeing the right voltage. Replace it. A working 02 sensor will improve mileage while cruising.

What kinda of model is the car, n/a or turbo. Change the o2 for sure, or disconnect it. I'm not throwing a check engine light or code for no o2 sensor. But make sure your bac is still working properly also.



^^ Weird. Maybe my car is just gangsta.

without the O2 sensor your gunna get like 7 mpg max drivin in town. its not cool.

Just how bad is your mileage? I have an S5 and I can't really get more than about 22 mpg on the highway. This car is still stock though.

I'm getting 320 miles per gallon. So it's around 17 mpg. No o2 sensor also. I haven't hooked up the wide band, so it can be ecu's o2 also.

Thank you all, I think Im getting about 15km per gallon ( I think its like 10mpg) Im not sure but its not 22mpg at all for sure neither close to it.

And what about the powerless and the bad minimun ( its around 1000 rpm and 200rpm) . I will check the Bac with the FSM (Do I have to adjust the BAC with the allen screw?? or its just electrical checking??)

I also got 1 error code , its trailing coil (change it? or check spark plugs wire or anything else?)

thanks again!

Replace the trailing coil. Without trailing spark, mileage and power will decrease, and it could make your idle rough too.