I'm getting codes for catalyst efficiency below threshold on bank 1 and bank 2. Before the motor swap, I was just getting a code for bank 1, now i'm getting one for both. FYI the car and exhaust has 165k miles, the motor's around 49k.

I had to swap the passenger (bank 1 ?) upstream sensor with one from the '06 because the connector got cracked in the chaos. I've got the other 3 from the '06 and i'm going to try swapping them in first, according to Motorcraft they're the same part.

What's the possibility all 4 of my cats took a dump at once? If the O2s don't fix it what am I looking at, cats?? FYI, I don't have a custom tune yet to make everything work well together. I've got about a month to get this thing inspection ready, stupid emissions inspection

If your scanner can monitor the O2 sensor outputs, check that they all are switching. I had 1 slow downstream sensor (Bank 1) on one car that caused both 0420 & 0430.

It can be the maf sensor, O2 sensors or the cats. I had this same problem on a 95 marquis. It gave me codes p0130 and p0131. After replacing 02 sensors, spark plugs, trying a new maf and trying a bounch of other stuff, car still had the codes and ran horrible. I then deceided to remove the catalyic converters passenger side and car ran extreamly new. Came to find out it was both cats on the passenger side that were clogged up to the max.

Yes, the entire top end is for the most part 2000. I'm under the impression i'll need a tune for the '06 MAF to work, when that happens i'm going to swap the entire air intake system for like an '04, or maybe the '06 if I can put in a port for the IAC.

Ford05, i'm thinking the pass. side cats may very well be clogged. I thought the driver's were okay, but they may have gone too. The old motor did burn oil like it was free.

I'm headed out now to swap the O2s since I have them on hand.

The 95 marquis I worked on had an oil leak a few months ago. Don't know for how long but when I bought the car, the seller did tell me that it had fail emission and they had to replace a few gaskets and spend a few 100 bucks. When replacing the sparkplugs, the passenger side ones were completly black while the driver side were very clean and looked new. I'm still guess that the marquis still has a leak(oil) and it just caused the cats on that side to clog up with gunk.

Check out this thread.....
http://www.crownvic.net/ubbthreads/ubbth...072#Post2264072

and the video link below.
http://www.youtube.com/watch?v=5icTmYItwiE&feature=related

Before you replace your cats!!

That's interesting reading/watching. I'm still not sure i'm sold on the idea of dumping lacquer thinner in my tank, but if it comes down to it I may. Custom cats are in the works, but not close enough for inspection.

I swapped the remaining 3 O2s and cleared it out. So far it's got 27 miles on it since then and -knock on wood- no CEL. It used to pop it in 4-6 miles. The front ones had a nice coat of some kind of white stuff on them, and the original rear one had rust inside the holes. We'll see if it holds, if it does it's getting inspected tuesday before it changes it's mind.

I know of one person who has done it and saw results......and the car was OK. 1 gallon in 1/2 a tank of gas is not much......but just enough to do the job.

i wanted to do this but wasnt sure about it. I did remove the cats a dumbed in a big bucket of water with detergent and that didnt help. It was just completely clogged up.

Its one of those things that you try when you got nothing to lose. If it worst your stoked.....if not then your at the same place you started at.

Well...it's back on. It blessed me with its amber glow right at the 40 mile mark. I went back to Advance and read them again just to be sure, it's the same 2 codes as before. I can fork out the money for new cats, so I'm going to jump in with both feet and try the lacquer thinner.

Just for fun I stopped by the firehouse and busted out the thermal imager to see what they were running. The following temps are inside the heat shield, with the motor running.

D/S Front: 366
D/S Rear: 382

P/S Front: 390
P/S Rear: 393

The pipe running between the two cats was right at 500 degrees on each side.

I'm still not convinced...I think i'll try like a half gallon first and run it out in one run the same day. Anyone else tried the lacquer thinner trick?

In the link to to the tread about this method.....at least one person has done it with there CV. The member who turned us on to this claims to have done it in 3 vehicles with great results.

Here's the link again...
http://www.crownvic.net/ubbthreads/ubbth...072#Post2264072