NeoLoco

When it rains heavily, and there are deep puddles, etc., my oxygen sensors go bad, and my car runs like crap. Is it possible that if the wires going to the weatherpack connector for the oxygen sensors got messed up a little bit when I put long tube headers in, that there would be some kind of arcing or something that would cause the oxygen sensors to go bad when it rains? Or is it probably just rain getting into the weatherpack connectors and messing up the o2 sensors?

I made sure that the weatherpack connectors were tight, and they looked water proof, when I installed the last set of o2 sensors. The o2 sensor wires are routed well with some zip ties and a couple wire mounts, so they're not touching the headers or anything that would damage them. I would hate to put new oxygen sensors in just to have them fail again when there is another heavy rain, if the cause is due to the wires leading to the plug for them.

If the wires from the PCM going to the plugs (that the oxygen sensors plug into) are messed up, how do you connect the new wires on the new plug to the wires from the PCM? It seems like running whole new wires from the PCM to the plug would be difficult, so would you just cut the wires between the PCM and the damaged part of the wires going to the plug, and solder new wires with the plug?

I've heard that NAPA sells the plug, and there are a few threads about the colors and functions of the wires, and there are also some plugs on eBay that have the wires attached.

Any help would be appreciated.

Formulated

iTrader: (16)

I had a problem with universal replacement sensors where water got into my shrink wrap and caused all kinds of grounding issues. TPS and other sensors all went bad.

I suspected the O2 sensor, and I felt confirmed when I drained a bunch of water out of the harness wrap. After drying everything out and cleaning it up, everything has been fine.

Be sure that everything is nice and dry.

NeoLoco

Yeah, I'll make sure the wires and connectors are dry and if I don't see anything wrong with the wires from the PCM to the plug on the car, I'll just install some new o2 sensors and put heat shrink wrap everywhere that water could get in. I'll update here sometime soon.

AmarilloWS6

iTrader: (3)

When I was running o2 extensions on my ws6 it happened everytime they got wet. I said screw it and put my stock o2's on my headers and re-pinned my PCM.

jimmyblue

iTrader: (11)

It might be electrical, but long tubes have a hard
time keeping the sensors lit even when dry. Hose
them down and the sensor goes cold.

cyberkill

I had the same problem. After troubleshooting, I pinpointed a section of my O2 extension that was just barely touching the header, and it burned right through the insulation. Whenever it rained or was really humid, or I went into a touchless carwash, my car would misfire, but if I went through a carwash on a dry day, it would eventually get better. So, i found it and replaced it with the Bosch Corvette Rear O2s, just the driver side.

I know you checked, but as a sanity check, what helped me pinpoint it was that I had the car running on a dry day and the car was running fine. I took a spray bottle with water and went under the car and sprayed a section of the wire like mad (especially near the bung where the O2 threaded into), then paused, then sprayed another section. Be LIBERAL with the sprays, just do it section at a time. The moment you hear your car misfire, you've narrowed down the spot significantly.

Honestly, I looked at the area where this burned wire was a dozen times, but I never saw it. It was only after I did the spray and I knew it was in that area that I was able to focus better and found the burned wire.

Good luck!

Oh, I did cheat a little. My friend had HP Tuners and I had him connect it to my car while I went through a touchless wash and was able to tell me it was driver's side. That obviously made it a little easier.

NeoLoco

After hooking it up to HP tuners, it was only the passenger side, and the connector was bone dry and clean as a whistle, so I didn't waste time/energy/money putting shrink wrap on the connectors, but I did replace both o2 sensors.

Amarillo, I had the same issue when I had o2 extensions. The slightest rain and the o2s failed. When I put the rear corvette o2 sensors in, I thought it was fixed, but the recent monsoons were the only heavy rain since I installed them almost a year ago, so I guess almost a year/12,000 miles isn't too bad.

CK, that's a good idea to check with a spray bottle or carwash with the engine running, and someone inside with a laptop and HP tuners would be perfect. I'm like a zip-tie king to keep wires away from stuff that could damage them, and when I went to put new ones in, I thoroughly inspected the wires and saw nothing wrong with the wires on the one that was bad, but it probably would not have hurt to check with your method.

JB, it seems that may be the problem I'm having.

Thanks for the advice and info. I'll hope for the best with these new ones installed. Luckily it was just within a year so they sent me new ones for free.

RevGTO

iTrader: (12)

Bringing this one back up. Heavy rains in Wichita this morning and I had to drive (carefully) through some fairly deep puddles and running water. Everything seemed fine, but when I started the car and drove later when it was dry I started getting misfires and threw the dreaded P0300 code.

I'm running Denso Corvette rears that are a year or two old. I presume one or the other or both is toast? I don't really understand how this could occur other than water getting into the weatherpack or a hot 02 shorting out by being dosed with cold water?

NeoLoco

I never updated this, but I found the issue that I was having. My O2 sensors were not tightened down enough. I didn't want to strip the threads in the headers when I installed the O2 sensors, so I didn't tighten them down all the way, but when I installed the last set (3 years ago), I was able to tighten them a fair amount more. I'm thinking there was a small vacuum leak that was drawing water in when I hit a deep puddle when there was heavy rain, which fried the sensors.

I checked all the wires, weatherpacks, and put electric tape around the wires near the O2 sensors for a little peace of mind, and everything has been fine since then.

Older O2 sensors may just be prone to failing during heavy rain. It's worth checking to see if your sensors are tightened down, not with crazy torque, but that they're not loose. Checking to make sure there are no vacuum leaks anywhere would be a good idea, although that probably wouldn't correlate to the O2 sensors failing in the rain. The wires and weatherpacks could also be the culprit.

RevGTO

iTrader: (12)

I typically torque 'em pretty darn snug, but I'll have to get under there and check if one is loose when I have time. In the meantime, I uploaded an open loop tune and am driving that way. (I drove this way for a year and a half some years back). It definitely identified the O2's as the culprit, since it's running fine now. In fact it feels like it's running a little leaner and torquier than before the incident.

Tahoegirl

So when i replace my o2 sensor that will work?

RB04Av

????

O2 sensors are an interesting device. They consist of a layer of a substance both on the INSIDE (exposed to the exhaust) and on the OUTSIDE (exposed to the atmosphere). As such, they don't actually directly measure the concentration of oxygen in the exhaust; they ACTUALLY measure the DIFFERENCE in the concentration of oxygen in the EXHAUST compared to the concentration of oxygen in the ATMOSPHERE.

https://en.wikipedia.org/wiki/Oxygen_sensor

The entire thread you posted to, except for the part about tightening (a COMPLETE red herring... true, they need to be tight, but that wasn't what ailed the original poster), was based on somebody dunking his sen-sore(s) under water probably due to having been moved from their OE location by his header install which put it/them into the path of splashing water, which deprived it of its exposure to the atmosphere. It can't possibly work right in that condition, so no wonder it couldn't run right. Too bad nobody posted about that 9 yrs ago when this first came up. Too bad also, he got fixated on the connector; another red herring. And like tightening, it's certainly true that if water gets into the connector it can make funny things happen, but it's not likely that the OP's issue was the connector.

No telling what your problem is, or whether "that", whatever it is, "will work" whenever you replace yours.