ok, the P160 code didn't show up on my last code scan, but the P2197 did still. I added fuel cleaner (tehcron) and filled up. Performance is up and down, sometimes it seems fine, then sometimes it seems like it hesitates a bit still.

What about a clogged fuel injector?

Would that be a possible problem/solution? I know the fuel pump/fuel filter is a possible and likely cause for this all, but I just want to eliminate wasting time/money if I do the fuel pump and find that the fuel pressure is still low (i.e. I don't want to drop $800 more to get a new fuel pump and not fix the problem).

 

A clogged fuel injector does not lower fuel pressure available. The fuel pump pressure test is done physically before the injectors. Replacing a clogged fuel injector will not increase fuel pressure. Your fuel pressure was below acceptable values. You need a new fuel pump or regulator (depending where gauge was inserted---see previous post).
If you replace the fuel pump and still have low pressure, then you have a leak or blockage somewhere (in fuel line, not at injector).

If anything, a clogged fuel injector will increase overall pressure as the fuel available isn't going thru the injector and backing up. But this is just extra tid bit as the test is done before it.

 

ok, thanks. i'll probably get the fuel pump done soon then. i'll talk to them about the fuel pressure regulator, but I don't think these guys really have a clue either. At a minimum, if I get it and it doesn't fix the problem, I'll argue for my money back since they replaced something and it didn't fix it?

 

Is there a fuel pressure regulator on the 6? I looked in the parts list I have for the car and location and this thread: Fuel pressure regulator - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum

doesn't appear so?

 

That link was for the Ford Contour.

A few searches and found these:
How to Check for Fuel Delivery in a Mazda6 | eHow.co.uk

Mazda 6 Fuel Pressure Regulators at Andys Auto Sport

03-08 Mazda 6 Fuel Pressure Regulators from Weapon R at Andy's Auto Sport
----this one has a gauge as well. it's universal. not sure if it's adaptable.

Standard Motor Products Standard Fuel Pressure Regulator - JCWhitney
Not sure on your year (you should add it in your signature, make one up). The last link works for 2006, not 2005. Different year may result different styles. Phone your local dealer and inquire is the easiest answer.

What is a fuel pressure regulator? Why buy a fuel pressure regulator?
The fuel pressure regulator regulates the fuel pressure that goes into the engine. The car's computer does not control the fuel pressure regulator; it is controlled by the engines vacuum. Depending whether the idle is high or low the fuel pressure regulator opens and closes giving more or less fuel. With a high performance motor, an adjustable fuel pressure regulator is needed to increase the amount of fuel given to the engine since larger injectors and fuel pump will be utilized.

 

Your best solution would be to phone mazda and ask them if and where it is located. See previous post.

 

yeah, I called and set up an appointment for Friday. They said the tech tested and said it was the fuel pump for sure and not the fuel pressure regulator. I recall you stating the fuel filter is built in, I'm going to verify when I'm there on friday that this is clear as well, want to cover all my bases.

 

Fuel Filter is in the Gas Tank attached to the Fuel Pump (part of it).
When you add fuel system cleaner in you have to be careful the little round cardboard piece under the cap of cleaner does not get in fuel tank. Sometimes the cardboard piece dislodges from cap you unscrew and remains on the bottle, and when you pour it in, that piece goes in your tank!
The filter should keep this out of pump.

 

yeah, always worried about that especially since i just jab my key in there if its that metal like covering. hah.

they said it might be a whole day type of thing? really, it seems like its a rather quick thing to do, who knows, maybe they'll let my car sit while they go grab coffee so they can charge me max labor. blah.

(testing sig too).


Another curious thing is that the p2197 code is for the bank 2 oxygen sensor stuck lean. when I looked at my freeze frame data, it said for Fuel System 2 it was "CL- Fault". I'm thinking this is why my recent sluggish acceleration is coming from?

 

First get your fuel pressure fixed. Drive around for 50 miles (minimum) before making next decision. You may have to change the first O2 sensor on that side before the pre-cat.
Another thing you may want to do is: EGR Modification/Optimization: - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum = EGR Tube modification cut in intake plenum. Please get new throttle body gasket and intake plenum gaskets when doing this.
Quote from that link: "one of the 2 cylinder banks will run significantly leaner than the other. How significant are we talking here? --it has been documented that there is about a 5%-7% difference in fuel trims between the front and rear banks".
This could be why 1 side is tripping lean and not the other.