catalytic converter and oxygen sensor replacement?

Kind of. If you say that a car or truck has 2 mufflers on the same bank, it sounds like they can't make a muffler good enough to do the job by itself. If you say that a vehicle has a resonator and a muffler on each bank, then it sounds like someone engineered the system to be that way. A resonator/muffler setup is not that rare. This is just a wild guess on my part, but I'd say that a resonator and muffler combo is used to improve performance with less back pressure or when they are trying to make a vehicle have a deeper exhaust note.

I'm in California, and they are expressly prohibited from checking my car for me, but they can let me use the tool to check it myself. If they will check the car for you, then even better because this takes away at least one level of difficulty.

Most of my tools fit in three drawers of a box that size, with the same exceptions for saws and drills and such.

I try to get quality tools when

I wouldn't buy stuff there that you plan on actually using. My brother likes that store, but I bought something there that is only needed for life and death situations, and it failed me. Thank God no life was lost, but it was very close. There's alot to be said for quality ...

it says 8yrs/80000miles on Toyota's website. My car has 139K on it, guess it is too late. WM

snipped-for-privacy@yahoo.com wrote in news: snipped-for-privacy@o13g2000cwo.googlegroups.com:

Why don't you take the car out for a good, hard hour's run (or more) on the highway at the highest speed you can get away with? For extra load, turn your headlights on, rear defroster, air-conditioning, and any other high- load devices I haven't thought of.

This will help cook off some of the crud that's impairing efficiency, and might just make that P0420 go away for a long time.

My tool box also has tools I've accumulated for work around the house. Building an addition on our last house was a good excuse to accumulate some woodworking, drywall, and electrician's tools. A lot of the stuff rarely gets used.

My parents are moving from a house to a condo and my dad has hinted that he wants me to take his tools. A lot of this stuff is probably more valuable to a collector, like wooden-handled Snap-On screwdrivers, a Blue Point drill with a cast metal case, hand-lappers for valves, a timing light with a pointed probe to pierce spark plug wire boots.

I think of Harbor Freight as more of a place for "disposable" tools and materials, like abrasive wheels for my cut-off tool, hammers to bring on campouts to drive tent stakes (the kids lose at least 1 a year so a $2 hammer is a lot less painful to lose than a $40 Estwing). I also buy leather gloves there to lend to people when I take people rappelling because a dozen pairs of rappelling gloves would cost $400. They do have some name brand stuff for good prices, like my Ingersoll-Rand angle die grinder.

Just run the car at highway speeds in 2nd or 3rd gear to keep the RPM up. A lot less risk of a speeding ticket that way.

"Ray O" wrote in news:b29e7$4344a3e9$180fead6$ snipped-for-privacy@msgid.meganewsservers.com:

I did not suggest that the OP exceed the posted speed limit.

Loading is the important thing, not revs. You need to feed lots of hot gases thrugh the cat. Just running high RPM at low-load will push lots of air through, but not much heat.

I also forgot to say that leaving your windows open will increase drag, and thus engine loading. This to be done as well as the other suggestions made above. This may seem like a belt-and-suspenders approach to heating up the cat, but the OP is probably in need of more than your usual cures.

This is a good procedure for the O2 sensor before the catalytic converter, but won't work for the sensor after the catalytic converter, if the converter is working. The output from the sensor after the converter varies much less since, if the converter is working, there should be little or no unburned hydrocarbons left.

Ed

If it is an OBD-II compliant vehicle it will have a sensor after the converter, or sensors after the converters. This sensor was added specifically to monitor the catalyst and is required by the EPA. I am not sure what year your Pathfinder is, so it may or may not be OBD-II complaint. At a minimum you will have two sensors before the converter (one for each bank of the V-6). If it is OBD-II compliant you will have one after each converter (2 sensors if you have 2 converters). I have seen older V-6s that only had one sensor before the converter, (in the Y-pipe, or immediately after), but this technique is out of favor because it takes longer for the O2 sensor to heat up in that location and it does not allow pinpointing an emission problem down to one bank.

Regards,

Ed White

Are you sure you aren't confusing resonators with the converters? I'll bet you have two converters very close to the exhaust manifolds and the items you think are converters are other elements of the exhaust system.

Ed

You should know by now that the last couple of years, Toyota has NOT used a conventional "O2" sensor before the catalyst. After the catalyst, same ol O2 but the input is only used for catalyst performance tracking. The current technology employs an exhaust sensor that operates on a different principle and is called an Air/Fuel ratio sensor. They are NOT interchangeable.

Some early fords had 6 o2 sensors...

yes, I was probably confusing the resonator with the converter as it doesn't make any sense for sensors #2 to be in that location if the resonators were the CAT.

"Ray O" wrote: snip

Gee no Ray, those things aren't something that I've fooled with much...are there any 'starters' in there?, some of the older models have a starter, a little cartridge can about half the size of a 35 mil camera film container. Usually made of aluminum and has two pins out one end. You 'twist to remove' them. They'd be prime candidates for change. I haven't seen those in a while though...if all four tubes aren't working then I'd agree that it's likely input power troubles... probably the wall switch or whatever controls them.

Be careful...115 VAC can fry you bigtime!...we'd miss your calm unflappable way of doling out good advice here!...