CEL PO171 and Secondary Air Injection Malfufuction Please shead some light If you can
 

Hey Guys,

I started my car this morning and the CEL light came on. I went to my shop here in KC to get a oil change and have the codes pulled. First is PO171 which is to lean and the 2nd is Secondary Air Injection Malfunction I have no idea what this means or how to fix it. If you shed some light on this it would be much appreciated. Thanks in advance. Car is a 2005 45,000 miles.

Could a bad MAF throw this code?

P0171 System too lean ON 2 Fuel system ´ (See DTC P0171 )
https://www.rx8club.com/series-i-tech-garage-22/rx-8-technical-info-cel-codes-pcm-pin-list-collision-guide-26291/

I doubt it's a bad MAF ... but it's possible.

More likely you have a bad rear O2 sensor ......

Thanks man. This might be a stupid question.. but where is that located

Rear O2 is located in the Cat

Don't know what your budget is like ...

Rear O2 is like 150ish

Your problem is hard to diagnose. If the car is running fine leave it if the cost to much.

Front O2 is in the 350 usd range.

U know u could have something wrong, I'm just saying in my experience the sensors are bad.
I've had to replace my rear O2.

Really u should try to do some more diagnoses.

Have u:
cleaned maf
Checked for vacuum leaks

yeah car is running perfect, power is good just want the cel gone if the rear is bad ill change that. I did clean the maf and did check hoses etc. Just dont want it to turn into a major problem. 150 is cheep to fix the rear. hopefully that will do it. fingers crossed

Let us know how it turns out...

I will thanks for the much appreciated help.

One more question sir so I found one online it a Bosch 18448-01100814 will this work or should i go oem? Or do you have any recommendations?

I'm not sure if that will work <shrug>
Is it much cheaper than the OEM?

The rear O2 is used to measure catalytic efficiency
The front O2 is an actually wide band O2

http://onlinemazdaparts.com/partloca...&siteid=214264

You should make sure your Secondary Air pump is functioning correctly ... here are a couple threads

https://www.rx8club.com/series-i-trouble-shooting-95/cel-secondary-air-injection-system-188496/
https://www.rx8club.com/series-i-trouble-shooting-95/p0410-secondary-air-injection-circuit-fail-173980/

Checked the air pump and it runs for like 2 min when its cold. So thats not it. Its a high pitched noise like the threads said. Code different though. Could it be my cat i know its a long shot but I think i will replace the o2 sensor and see if that changes anything if not ill go after the air pump and really make sure its up to spec. thanks man

FYI, rear 02 sensor has nothing to do with fuel trims, its there to monitor cat effeciency. Front 02 sensor is the one related to air/fuel ratio.

Replacing the rear 02 wont fix anything for your lean code.

This thought had occurred to me ..... the front O2 is a bitch to replace

Replace your coils and plugs. more on coils.

case closed.

so the lean code could be caused by bad coils and plugs?

would throw that code?

@cam, now we are talking a 350 dollar part, makes sense though thanks man. So coils and plugs and a front o2 sensor sounds like a start and to sell one of my bmw's haha

Just got this code, how does your car act??

If your cat is not working correctly you should get a Catalytic Efficiency code
P0420

But not necessarily

Cat is working great. Just had a smog test and blew uber clean.
No, i just got the P0171 code, no others. Imma check the vacuum lines and lines to the intake to make sure they are ok first.

Don't know if you have got it figured oh but I just went threw a month long battle with Mazda because I had this code they changed both o2 sensors and gave it fuel injector cleaner like three times then I was good.

sweet I still have it but my engine light comes on then goes off so I dont know what the deal is. What did they charge you for that if you dont mind me asking

No power loss or shuddering

Another code popped up. P2070. I clean the valve and both codes are gone. The car idles much nicer.