OBD-II p0133 & p0430?

Question

Vehicle: 1998 Mercury Mountaineer AWD 5.0L 8cyl, 116,000 mi. In my possession only for a few months. Previous owner cannot be reached (overseas).

1-For about the first 5 minutes, exhaust condensation is visible in the evening air when other cars' exhaust is invisible in ambient air (~55 F). Exhaust is pale white in color, almost like steam. There is water discharged from the tail pipe the moment the car is started.

2-OBD-II P0133 [O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)] & P0430 [Catalyst System Efficiency Below Threshold (Bank 2)] intermittently. Most of the time I get one or the other, but not both. Usually I only get these under moderate throttle load while going uphill.

note: I thought it was due to a hole in the exhaust line so I had the pipe, muffler, and resonator replaced.

3-Under hard acceleration, I can "hear" the motor as if there is sound being leaked somewhere. This sound is separate and distinguishable from the motor signature from the motor compartment.

I had the impression that part of the converter's job was to convert harmful gases (namely unburned gasoline & carbon monoxide) from the engine exhaust into other elements, one of them being water?

I mentioned water escaping from the tailpipe at start-up as a positive sign that the catalytic converter in my truck was still on the job. If that is true, then why would the presence of water dripping from the tailpipe be a symptom of a problem? Is there something here that I'm missing?

Answer 1

Exhaust condensation and water droplets from exhaust is perfectly normal, the water is condensation in the exhaust after the vehicle cools down, upon startup it pushes it out the tailpipe, until the exhaust pipes get hot enough to evaporate it.

Answer 2

Yugie's right on the condensation, The p0133 lean bank one would have to be checked out as it may be a sensor or it may be that you have a air leak somewheres causing the code.... Each time it sets the code, it sets also some readings when the problem was caught by the computer and that will lead to seeing if it's a lazy o2 sensor or another issue such as a leaking intake gasket.

The leaking noise, I agree with the woman can be a exhaust manifold as those were known for cracking sometimes, and Actually I would have expected the lean code to be on bank 2 as that is where the cat code is.... (if it's a cracked manifold)

The cat code, can be due to a blocked or leaking exhaust or a lazy o2 sensor.. but my guess is the leak.... as I've seen the code under all three of those times personally.

Most shops rather change all o2 sensors to try to kill any problems... but the fuel economy on them things are crappy sorry

I think the o2 sensors are leading you to the problem than the problem but would take me to physically look at it to find out exactly

Answer 3

The Trucklet needs new #1 O2 sensor on the side of the engine where #1 plug is. And the other side of the engine front cat converter is weak. There are three or four O2 sensors on that trucklet. Replacing the correct one is essential. Having worked on cars a long time here is what I would do. Replace the #1 bank one O2 sensor. Then replace the #2 O2 sensor on bank #2.
The #2 sensors check the front cat converters the #1 sensors check fuel mixture. Just went Thur this on neighbors Ford Explorer

Answer 4

The P0430 code is indicative of a failed catalytic converter, I have never seen it any other time, except for when the converter has failed. I would have the converter assembly replaced, either with a used unit or a much more expensive new one. The only O2 sensor I would replace is the bank 1 upstream O2 sensor, which is what the P0133 code indicates. Also, the newer models require a powertrain control module reprogram for the P0133 code, there probably is an update for your PCM that can be done after the O2 sensor is replaced.

Answer 5

The white exhaust is an indication of anti freeze in the combustion chamber. The water discharge is also suspicious.
A small leak in a head gasket, that doesn't interfere with engine performance, can be causing some of your problems.
I would agree that the sound you are hearing, not knowing the nature of it, may be an exhaust leak or maybe from a leaky head gasket.
Check your oil dipstick for moisture. Check in morning before starting, pull dipstick and check for condensation, which would indicate moisture in crankcase. It should not be there,
I would guess you know water and oil turn a milky color.

Answer 6

Check for a cracked left side exhaust manifold. Due to the manifold's complex curve and shape in order to fit and clearance the steering shaft, it's pretty common to crack around the runners, usually between #6 & #7 exhaust runners.