P0430 code. 02 sensor locations?

[ForTheHordeKT]

Getting the P0430 code. "Bank 2 under threshold". I want to try replacing the 02 sensor throwing this code before I blame the catalytic converter. Was wondering if anyone could tell me where this was? Is bank 2 a specific side? I haven't been able to pull up a good diagram on google that would show me which sensors are which.

 

[Drewmcg]

The "bank" refers to the row of cylinders (left=driver's side; right = passenger side). Bank 1 is the bank where the No. 1 cylinder is; Bank 2 is the other bank. On the 4.0 SOHC (and I think also on the 4.6), Bank 1 is on the right side.

If you get a code reader (cheap), or even better a cheap bluetooth OBD II reader and the Forescan app, you will be able to see whether its an O2 issue without even crawling under the car.

 

[ForTheHordeKT]

You know, I've been tempted to order up one of those bluetooth OBDII's and a companion app. Sounds really useful to have and I have both this Explorer, and a 2016 Mustang GT it'd be handy for. This Explorer keeps the Mustang out of the snow considering I picked it up pretty damn cheap by the winter of 2016. Paid only a few hundred more cash for it than I'd have paid buying snow tires and their own rims (for easy mounting at home) for the Mustang.

So bank 2 would be driver's side then. Hell, it's a moot point now lol but maybe my question can stand for people who do need to isolate a particular bank. I went out to Autozone today intending to buy an upstream and downstream sensor. Had them pull the code again just to see if it'd specifically call out a particular sensor or just vaguely tell me bank 2. A second code pulled up that I didn't get so many months ago when the service engine soon light originally came on. Now I'm getting P0430: "Catalys System Efficiency Bank 2 Below Threshold" which was my original code. Could be the converter, I want to try my luck with the sensors first. Today I also pulled up P0133: "H02s-11 (Bank 1 Sensor 1) Circuit Slow Response". So god damn it, I got issues in both banks. So screw it, I bought the sensors for both banks and tomorrow I'm going to have some help getting under here and just replacing all the *******s. I could probably get away with not touching the 2nd sensor on bank 1 but you know what, if I'm already replacing 3 I may as well just hit them all. I've got like 217,000 miles on this thing so if it doesn't get done now it might not be too long before that 4th sensor will want my attention anyways.

 

[imp]

@ForTheHordeKT
If your cat converters are original, never replaced with such high mileage, the multiple O2 Sensor codes you are getting are possibly due to loss of cat efficiency. Easiest to replace the Sensors first, just in case, but my '04 did the same thing, and replacing sensors proved useless.

A word of caution, yours is an '03?, the connectors at each sensor are clipped in place up on the transmission, quite difficult to get at. I broke loose the plastic clips holding them up there using a long screwdriver, then it's possible to grasp the connectors with fingers or pliers. They have a spring-loaded clasp holding them from coming apart; it must be depressed while pulling the connector apart to disconnect. The rear O2 on passenger side has a heat shield in the way, held by 3 bolts, helps to remove it. Good luck! imp

 

[ForTheHordeKT]

Yeah, that's what I'm afraid of lol. I have no clue what was or wasn't worked on in this vehicle's life. I bought it used at like 214,000 miles or so two winters ago. Got my 2016 Mustang GT at the end of April 2016, and had traded in a 2006 Mustang GT for that. I'd always just dealt with the snow in the '06 GT. But I got the performance package on that 2016. Which came with summer performance tires. Wasn't gonna handle in the snow so well, so I could either spend about $2200 getting snow tires, separate rims for them so I could swap them out at home easily and not have to cram 4 damn tires in a Mustang and take them to a shop to do it for me each time, and the TPMS sensors for it. Or for $2500 out the door, I got this Explorer and can just enjoy 4x4 plowing over the snow no problem. Just a really high mileage and already heavily used Explorer lol.

Hopefully the sensors do the trick. The sensor 1 on bank 1 definitely needs to go with that one code. But with the original P0430 I was getting, yeah. Cat replacement could be in the cards. Just hope it's not.

And thanks for the heads up lol. Going to be headed over to my brother's house to get it done today. He's got a nice garage out of this snow to use, and a little more knowledge about these things than I do.

 

[Drewmcg]

Cats fail more often due to fuel system or timing issues than just mileage, but anything is possible. I wound up replacing both of my cats, but now believe only bank two was bad (due to old engine dumping raw fuel in that cat which ignited in the cat, destroying it). Failed cats can break apart and clog exhaust.

If you decide to replace one or both cats, cheapest fix I found was to call I around to find an exhaust shop willing to "splice" (weld) in generic cats @ $500 or less apiece. You may need to removed or replace the resonator and replace the muffler if cat debris has clogged them.

 

[lincolnshibuya]

sometimes the p0430 codes will go away if you just drive the car longer, I have that sometimes show up on my 98 lincoln continental and I believe it's just moisture/corrosion buildup on the sensor when it's not driven a lot.. I'll try reset/clear it first before replacing the downstream 02 sensor.

 

[ForTheHordeKT]

God I hate how those 02 sensors were positioned and aimed lol. At the tops of the pipes pointing downward. The two types of 02 sensor sockets I found at Autozone were both useless lol, had to attack it with a open ended 22 crescent wrench. And the upper drivers side plug is a beast to reach. Can't get your hand far enough up there between all the rest of the crap to reach that electrical boot it plugs into. To anyone else looking to tackle this, at the very least you're going to want some help doing the upstream driver's side sensor. We had to pop the hood, take off the plastic cover over the engine, and I got under there and spotted the green little 02 plug and shined my little light on it. Had my brother up there fumbling around the firewall chasing my light until he grasped the boot and pulled it up. Had to remove the 02 sensor and plug it into that boot first, then he fed it down to me and we just had to put it on and tighten it up with the sensor already plugged in to the electrical boot. So just FYI, save anyone else the trouble of even putting the damn thing in first before trying to plug her in.

Now I'm just gonna drive and wait and see what happens with my code. I suppose after a while I'll just unplug and re-plug the battery to clear it and see if it pops back on if it doesn't clear on its own first. But does anyone know offhand what the drive cycle is before it ought to clear its self? If that code don't go away, it looks like some catalytic converter swapping is gonna be in the cards for me.

 

[Drewmcg]

O2 sensors are monitored by OBD II constantly; not sure of criteria for turning off check engine light; even if it goes of it won't clear the code history.

Neither will just disconnecting battery. If you do not have access to a code reader that will clear error codes, you can reset all by disconnecting negative battery cable, put a rag between it and negative post, and clipping a small wire with alligator clips between positive post/cable and negative cable for 10 minutes.

 

[Drewmcg]

... Bear in mind that above technique will reset shift points, etcetera, too.