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Rav2driver

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Discussion starter · #1 · (Edited)
2009 RAV4 (actually a RAV2 since it’s front wheel drive) with the 2.5l
I’ll start at the beginning.
Car ran fine for a long time with 0 issues.
One day, it wouldn’t start, checked fuses and the starting fuse was blown wide open. Didn’t have a fuse or money for one at the time, and sacrificed my radio and horn fuse to put it into the starting position. Starts right up, but engine light’s on and she’s running rough. Scan said running rich, so when I got the money after a year or so to replace my MAF sensor and my bank 1 O2 sensor, light stayed on and ran lean since then.
I’ve replaced the o2 sensors and MAF sensor multiple times as well as putting a throttle body in. I’ve taken the air snorkel off the air box and throttle body to Saran Wrap it in case it was leaking extra air into the system. I’ve reset the lights multiple times with one of the best scanners Bridgestone money can buy. I’ve done the battery reset thing even. I can get the lights to stay off for a while, but it always comes back. The light typically comes on after it warms up/gas gets to about half a tank(?). It’s hard to pin down exactly what trips the light when it comes back on. I’m really hoping someone has experienced this themselves as well as what solved the issue. Thank you for taking the time to read the long story, but I figured the more info I can give the better.
Edit: short term fuel trim was around -6, long term was around 39. It’s always bank 1 that trips the light. Oh! And I also put a new fuse into the horn/radio slot, but the radio still doesn’t work or even light up (not at all the main concern though).
 
Discussion starter · #3 ·
I’ve replaced both the O2 sensors. There are only 2 sensors that exist on the vehicle as far as I can tell, the one below the heat shield on the manifold, and the one right before the catalytic converter. So bank 1 and 2 have one sensor each. Diagrams I’ve seen only show 2. None of that makes any sense.
 
I’ve replaced both the O2 sensors. There are only 2 sensors that exist on the vehicle as far as I can tell, the one below the heat shield on the manifold, and the one right before the catalytic converter. So bank 1 and 2 have one sensor each. Diagrams I’ve seen only show 2. None of that makes any sense.
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I’ve replaced both the O2 sensors. There are only 2 sensors that exist on the vehicle as far as I can tell, the one below the heat shield on the manifold, and the one right before the catalytic converter. So bank 1 and 2 have one sensor each. Diagrams I’ve seen only show 2. None of that makes any sense.
Typically a 4 cylinder engine only has one “bank”. Bank 1 sensor 1 and Bank 1 sensor 2 are your designations.
 
There were some specials that did have 2 banks even on the 4 pot engines - it is obvious if you look underneath and see 2 cats tho.

As above, you will need OE/OEM O2's, MAF etc as non branded parts will play havoc with our Ravs.

I also agree with the above WRT the O2's. It is worth noting that if you replace one with new, it may fool the ECU as the old O2 may be lazy/old and hence throw codes.
 
I’ve replaced both the O2 sensors. There are only 2 sensors that exist on the vehicle as far as I can tell, the one below the heat shield on the manifold, and the one right before the catalytic converter. So bank 1 and 2 have one sensor each. Diagrams I’ve seen only show 2. None of that makes any sense.
Did you use Denso parts? They're the OEM maker for the sensors.
 
Discussion starter · #9 ·
Did you use Denso parts? They're the OEM maker for the sensors.
I know for a fact one of them was. And that’s what I was trying to find out too, which brand would be OE. The MAF sensor I’m almost 100% certain is Denso. The last O2 sensor for bank 1 was a Walker, but the downstream is a Denso for sure. Thank you for the advice.
 
I know for a fact one of them was. And that’s what I was trying to find out too, which brand would be OE. The MAF sensor I’m almost 100% certain is Denso. The last O2 sensor for bank 1 was a Walker, but the downstream is a Denso for sure. Thank you for the advice.
I know a lot of people who have had problems with anything except DENSO 02 sensors. Denso is the OEM maker.

Find your part number here and then search to find cheapest price.
Amazon might have it

 
Discussion starter · #11 ·
I know a lot of people who have had problems with anything except DENSO 02 sensors. Denso is the OEM maker.

Find your part number here and then search to find cheapest price.
Amazon might have it

Thank you very much. I definitely see why I didn’t pick that one once I saw how much they were. Definitely going to save for that though.
 
P0171 can be caused by:

Intake air leaks
Fuel injector blockage
Faulty Mass Air Flow (MAF) sensor
Faulty Engine Coolant Temperature Sensor
Faulty Air Fuel Ratio (A/F) Sensor (Front Oxygen Sensor)
Incorrect fuel pressure
Gas leak from exhaust system
Faulty Positive Crankcase Ventilation (PCV) hose connection
Air Fuel Ratio Sensor harness is open or shorted
Air Fuel Ratio Sensor circuit poor electrical connection
Faulty Engine Control Module (ECM)

I suggest we go back to the basics to start with, then move forward.

With live data and a cold engine, are your coolant temps, air temps and baro readings plausible?

What are both your short term and long term fuel trims at idle and at 2500 RPM when the engine is warm? - looking for vacuum leaks here

Do you have any exhaust leaks? Especially from the manifold to rear O2 sensor?

Is there any evidence of harness damage from the O2 connectors back to the ECU? Are the connectors clean, or is there any evidence of green crusties

This would be a base start, and we can go from there
 
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