Drove through some water! Car runs rough, wants to stall!

[DJ Hellfire]

There's a road by my house that floods when the ocean tide is high! I live by the beach. On my way to work yesterday (this is the only way), I drove through it really slow and about a block later, the car started stumbling a bit but kept driving fine. About 4 miles later, I go to take of from a red light and the car just wants to die, but doesn't. RPMS just drop and the engine doesn't respond at all to acceleration. Let it sit a little and it smooths out and let's you drive again, but most times will not go over 40mph without bogging down. If I gun from a stop, sometimes it will just keep accelerating until I let go of the gas, then the pedal is unresponsive again for a few seconds until I let the stumbling smooth out. Never stalls though.

Now, my car is lowered (on Spring Techs) and I have a CAI, but the water is only about 5-6 inches deep. The water barely comes up to the body of the car and the filter is above the foglight. So the engine didn't suck up water. Filter ways dry. Check engine light came on and I scanned it. Had 6 different O2 sensor code; no activity, high voltage, heater circuit malfunction, yada yada yada. Codes were for each O2 sensor (3 codes for each sensor). Basically both sensors are reading the same problem. Looked at the data stream and both sensors are pinned solid at 1.27v. I just replaced the front sensor earlier this week because it had the high volts code and was stuck at 1.27v as well. Put the new sensor in and it was fine, back down to a normal 0.03-0.05v and ran perfectly fine until I drove through the water yesterday. Also, I replaced the secondary O2 back in December. Car has 153,000 miles and both sensors were original.

Also, I have a header and both O2's are extended and are at the very bottom of the car, in case you guys are wondering how they got wet. Connections are good and sealed against water. Thing is, I've been living here for 5 years and drove through the water several times over the years and never had this issue! Even plowed through a bunch of snow over the years.

Anyway, I'm kinda skeptical to just replace both sensors again as it seems highly unlikely that both just went bad from water, although they were probably submerged. Never seen that happen, but who knows. Anyone have any other ideas? Checked all the fuses. All good.

[mlumz]

Are you sure the filter didn't get wet at all? If it did you need to let it dry out. Also you need to make sure the wiring in the engine didn't get wet either.

[DJ Hellfire]

The engine bay was completely dry. Besides, I've power washed the engine bay, spraying soap and water directly all over the engine, which is part of an the process of an exterior detail, and never had an issue. As far as sucking water, I was thinking maybe it sucked in water and pushed it out the exhaust and damaged the sensors that way. But when it smooths out, it runs normal and has great power. And from my experience as a mechanic, engines rarely survive liquids in the combustion chamber. The engine doesn't knock or rattle or nothing weird. Just intermittantly shakes like a bad misfire then smooths out. Has to be something electrical. Plus, like I said, the water barely reached the body of the car, and the air filter stops above the fog light. So the filter was still about 5-7 inches above the water.

[songee623]

just tossing it out there coil pack maybe going bad

[DJ Hellfire]

Thought about that. But I've never seen a bad coil completely disrupt o2 operation. Plus bad coils typically cause misfires and makes the CEL flash. However, when I gun it it does have misfirey smell from the exhaust most likely due to the lack of proper primary o2 operation.

[fenixignition]

all i can think is maybe something along the line of the exaust might have a crack by the 02 sensors, which could explain why water didnt effect it before, but does now.

[DJ Hellfire]

all i can think is maybe something along the line of the exaust might have a crack by the 02 sensors, which could explain why water didnt effect it before, but does now.

Good idea. I checked and there is a very small leak where I had a cap off welded in the stock rear o2 sensor bung. It's about 10" from the front o2. However, the leak is so small, I can't see how it would let enough water in to do any damage while there is exhaust puffing out the same hole. Plus, it's at the top of the pipe, where I don't think was submerged. Lastly, catalytic convertors generate water by nature during operation, even more in the winter, which contacts the o2's as well. So it's a bit hard to see a small amount of water killing 2 o2's. Unless maybe because it is salt water?!

[avantegt]

When salt and water are heated, and they cool they can cause salt crystals form when cooling.
Maybe when the salt water cooled the salt covered the 02 sensors?

[fenixignition]

along with sudden temperature change. hot pipe meets cold water.

[DJ Hellfire]

Well, turns out the O2's did get fried. Instead of gambling with OEM sensors from the dealer, I got a couple of NGK sensors from eBay for $50 each. Popped the upstream one in and it ran perfect. Drove it for two days perfectly and started running like crap again. Checked O2 sensor data, still working perfectly. Now getting a P0506, Idle below spec. Most likely an IAC motor. Pissing me off! Thanks guys!

[songee623]

glad you found out what it was.

[DJ Hellfire]

Thanks! Yeah, man. Time to trade this ***** in. Car's been reliable for all these years and now stuff is starting to fail. Alternator is basically shot, the power steering lines are rotted, the body is rotting, timing belt and water pump are due, trans flush is due, gonna need brakes soon, Springtechs are sagging, and mostly everything on the car is original. So I know more **** is bound to fail soon. Not really worth it for a car that's only worth 1000! Plus got two kids now and need something bigger. Bout to start taking all my goodies off the car. Going to have a good amount of stuff for sale! Going SUV shopping tomorrow. It's been nice!

[avantegt]

Go for the new Tuscon. I got to drive my moms last night, and it was really nice. The drive by wire or whatever it was called is kind of touchy though.

[DJ Hellfire]

Need 7 passengers! Looking into the Durango R/T.