CAT O2 Sensor voltage HELP

I got my 355 back on the road after fiddling with the alternator belt for 2 weeks. I took it for a nice 50 mile test drive today and everything seemed to be fine. I need to drive my car next week from LA to Vegas and get an emission check in Nevada. The last thing I needed was a Check Engine Light which just came on.

I looked at my code scanner and I got a Bad Cat fault. Never had one before and certainly don't need it the week before an emission check. I reset the codes and it hasn't come back on yet but its only been about 20 minutes. Regardless, I need to be able to pass emissions so that is my concern

In looking at the O2 sensors, with the car idling around 1,100 rpm, on bank 1, sensor #1 ranges between a low of .09v and a high of .79v while sensor #2 is ranging from .09v to .73v.

On bank 2, sensor #1 is in the .07v to .76v range while sensor #2 is in a very tight .09v to .12v range.

Showing this much fluctuation with sensor #2, does it sound like I have a problem with the bank 1 CAT?

Anyone ever have any luck with either a spacer on the #2 sensor or in cleaning the CAT? I have only a week to get this car in condition for a 300 mile drive and then passing the smog.

Suggestions?

 

Unfortunately I was too quick on my code reader in resetting to see if the code would go away. It did say it was a CAT fault and not an O2 sensor but I'm using Torque program and I don't know how sophisticated that is.

To answer some of the other questions, no there is no white powder on any of the exhaust tips.

I know very little about what voltage the sensors should be reading. On Bank 2, Sensor 2, the range is very tight between .07v - .12v. That seems to be very little movement. Shouldn't it be much closer to the .5v range with fluctuation around that? The fault code said CAT but there seems to be a problem with the O2 Sensor reading. Is that a bad cat causing that or could the O2 sensor be faulty? If the sensor was faulty and not the CAT, would I be getting a O2 sensor code fault?

Should I pull the Bank 2, Sensor 2 have see what it looks like? Maybe bench test it?
By the way, which side is Bank 2? Left or right?

If it is the sensor, is it a readily available part - non-dealer item? I see part numbers on the 348 page. Is it the same for the 355? Anyone have a suggestion of a source? I need this cleared up by next weekend or I am screwed.

 

Which side is Bank 1 and Bank 2? Is bank 2 on the left from the rear?

Since I am getting a low reading range out of the post cat bank 2, does that seem like it is working but cold be other problems or will a faulty post cat sensor display a low voltage range?

Problem here is that I have 6 days to get this cleared up and I am scheduled to drive it next Tuesday 300 miles for the emission check.

 

Trying this tonight. Already ordered a new Bosch OME post CAT O2 sensor online just to save time. If its not the problem then I'll look elsewhere.

 

Thanks. Im having the emission test done by Wynn Penske Ferrari in Las Vegas. Several members swear by them that they can make it pass as long as there are no prohibitive faults. I'll try the procedure but no telling if they will have the car sit before testing or what they do but I spoke with the service manager and he seemed optimistic.

As for the sensor problems, I pulled out both of the O2 post cat sensors, wiped them off with a paper towel (one had some white dust) and switched their locations. I then had the car running for about 15 minutes to heat up and now both sides seem to be reading OK. Both post cat sensors are now in the .12V to about .73v range but seem to hover more in the .15 - .53 range. Pre-cats are between .09v - 1.0v.

Someone please confirm but they seem to be working now? Could it be as simple as wiping them down?

On a related question, is the actual cat sensor prone to failure (the one next to the post cat). I removed them to have better access to the O2 sensor and wiped them with a towel as well. One of them seems to have stripped threads and may be allowing a slight amount of blow by. Will this cause any problems? The stripped threads look to be on the cat plug side not on the sensor.

At the moment, I have had not faults since the reset but the car has only run for about 1/2 hour with maybe 3 starts. What I am getting now is a "pending Code P1115" Power train. Anyone know what can cause that?

 

Sounds like I should just replace all 4 sensors and have the cats looked at. The sensor that I just ordered is one of the post cat ones and if code 1115 is correct, its pending for a pre cat sensor, both of which seem to be working. Regardless I don't have the time to get them and replace before I have to go to Vegas next Tuesday. Hopefully the "pending" code will not turn into a fault by then.