I have a 2004 Mazda tribute V6. I keep getting a code for the purge control valve circuit, p0443, and all 4 of the oxygen sensors, and the HEGO fuse blows as soon as I turn on the ignition key. I have disconnected each of the O2 sensors to see which one is tripping the fuse to no avail. Any suggestions?

 

There's a short to ground somewhere in the wiring before the sensor connector.

Grab a volt meter, with the fuse out check/remember which side/leg of the fuse is 12v. Shut off the power, leave fuse out, switch to Ohms on the meter. One lead on the non 12v fuse side and the other to ground, if the resistance is near zero, there's a short somewhere after that point. You'll have to trace the wire and find the short.

Before your tear open wiring harnesses, check the exposed wires first backwards from the sensors. YOu could also check for a short from each of the sensor connectors as that will narrow it down.

 

Thank you! It was a short in the wiring. For about 6 to 8 inches from the connector up the wiring harness the wires were fried. I bought a new connector and spliced it in with some new wire. The fuse doesn't blow anymore but now I have a DTC p2197. I'm at a loss. I have checked for vacuum leaks. I've inspected the wiring. Let me catch you up on what's happened up to this point.
My car broke down 3 months ago, over heating, but now effecting the temp gauge. Instead showing a little radiator symbol on my dash. I didn't research the symbol so I replaced the water pump and the thermostat. It was still getting hot after that repair, but now I noticed transmission fluid coming out the dipstick flute. I inspected the trans oil cooler and found and repaired some cracks in the trans oil cooler line. Still not running right. I thought I noticed some spacing between the exhaust manifold and the engine on the front exhaust manifold. Removed it and the cat inside was toast. Replaced it and the 2 O2 sensors attached. Found out the cause could be bad coil packs. Replaced all spark plugs and coil packs. Now there's a DTC p0443 for the purge control valve circuit. I stupidly replaced the purge control valve and all of the vacuum lines. Now here I am, with a DTC p2197. I'll attach screen shots from my code reader. No need to tell me





I'm an idiot. I know. But if you have something useful that will help I would be soooo grateful.

 

FIX CODE P2197 O2 SENSOR SIGNAL STUCK BIASED LEAN BANK 2 SENSOR 1

 

I replaced that sensor. That would e the front of the engine, the top sensor, right?

 

The code may not be due to a bad sensor, the engine may just be running lean and flipping the code.

• The P2197 code stands for “O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 1),” which typically means the powertrain control module (PCM) detects that the air-to-fuel ratio is too lean.
• Possible causes of the P2197 code include damaged or corroded oxygen (O2) sensor circuit wiring/connectors, a faulty bank 2 heated O2 sensor 1, and a fuel delivery issue.
• An illuminated check engine light, low engine power, and engine misfires are common symptoms of the P2197 code.

If I owned it, at this point, it's an old car, if it runs, drive it...lol!
If you want to mess with it, investigate whether or not it is running lean.

This should keep you busy; reasons for running lean:

• Vacuum leaks – Unmetered air enters the intake, throwing off the mixture.
  
• Faulty oxygen sensors – Incorrect readings can lead the engine to reduce fuel delivery.
  
• Dirty or clogged fuel injectors – Reduced fuel flow starves the mixture.
  
• Weak fuel pump or pressure regulator issues – Insufficient fuel pressure leads to a lean condition.
  
• Faulty mass airflow sensor (MAF) or manifold absolute pressure sensor (MAP) – Incorrect readings can cause an improper air-fuel ratio.
  
• ECU programming issues – Sometimes tuning or sensor calibration can lead to a lean condition.
  

 

Thank you. It does run, but too rough to drive comfortably. As much as I have messed with this car already, I'm not stopping now.
Vacuum leak: I have replaced all of the vacuum lines and the upper and lower intake manifold gaskets.
The O2 sensor is new. The exhaust manifold it is attached to is new as well. I replaced the wiring and the connector for the bank 1 O2 sensor that was blowing the fuse.
I've replaced the coils and plugs.
I don't want to throw more parts at my car but at this point I think I am looking at a MAF sensor. Unless someone has a better idea.

 

If it runs better when hot, the manifold can have a microcrack that closes as it gets hot.

Be sure the EGR system/hoses isn't allowing a vacuum leak. I would pull the hoses off the intake and cap them as a test.

You need to read the MAP sensor and be sure it's within spec while running (Manifold Absolute Pressure)

I would check the fuel line pressure to rule out a clogged filter or weak pump. You can borrow the kit from an autoparts store for free.

You could also have clogged/dirty injector nozzles which reduces fuel delivery causing a lean and rough running condition.

Anything could cause too much air, that's what you need to check.

When was the last time you disconnected the battery? No power resets the computer, driving after that and it will "relearn" fuel ratios and other stuff. Disconnect battery for an hour. Also, I've seen week batteries cause weird problems so have an autoparts store test the battery.

 

If you suspect the MAF just disconnect it when it's running and note any change. Then post back the result. The ECU will substitute a fixed value to keep the engine running. Parts darts can get very expensive.

 

Smart man! This morning I unplugged the MAF sensor while running and the engine bogged and almost stalled. It corrected when I plugged it back in. Unfortunately I did not have my code reader plugged in at the time so I don't have any numbers.
Oh, and there's a misfire when I first try to start my car. This is driving me nuts.