Do you know what the voltages are and is this a good indicator of whether or not the sensors are bad if the readings are off?Tech wrote:just search for the P0463, you'll find TONS....including at least a couple how-to's.
The front "02" on R51's isn't an 02, it's an A/F sensor, which works on completely different voltages than the conventional 02. As long as you don't mess with the primary cat between the a/f and rear 02, you can do whatever you want to the rear cats. You don't even really need to worry about keeping B1 and B2 balanced. The injectors aren't batch, but sequential. The ECM will take care of it. If you bust out the matrix from the cat, make sure you do a COMPLETE job. The broken down material can get sucked UPSTREAM ( believe it) and turn your engine into an oil burner.
I'll probably get the ECM relay replaced at the dealer, check my spark plugs, do the vacuum test, and test the AF/O2 sensors if they can be tested. Then move to inspecting the cats last.disallow wrote:There are 4 cats, 1 between the FA and O2 sensors on each bank, and 1 after the O2 sensors on each bank. I think they just clean the exhaust more.skwerl wrote: The article states there are 4 cats on an '05 are you saying their is only one primary and two secondaries?
It has some good info on how to test the cats if you have an infrared thermometer. I may try that but I still plan on taking them off anyway to try and look at the honeycombs.
You say not to mess with the primary cat between the AF and O2 sensors. I assume you mean not to remove the honeycomb inside the cat, right? Since it has to function and give correct readings between the AF and O2 sensors. If that one is bad, I'm pretty much going to have to buy a new one. What's the chance it's just a bad AF or O2 sensor?
A bad O2 sensor (post cat) shouldn't have any effect on how the engine runs. It just monitors the performance of the CAT and flicks on a code if its not.
I replaced my FA sensors last summer to see if it would help my fuel economy. The voltages read from my Cortex were exactly the same after I replaced them. I got better fuel economy for about 3 months, then back to the same $#|tty mileage.
Out of curiosity, what's your temperature range where you live? A span of three months, if you're temps were getting much colder it would probably be a contributor to worse fuel economy. In summer here I can get 22-23mpg highway (using the on-board gauge) and only 20-21 tops in winter due to the denser air and worse wind resistance.
I just remembered, my wife was low on gas one day and accidentally put about 1/2 gallon of 2 cycle gas to get her to the gas station but that was several weeks ago. I wonder if that could've caused plug or sensor fouling? From what I've read, that little amount of 2 cycle gas driven for a short time then being diluted heavily after a gas station stop shouldn't ruin cats. That maybe could explain why both codes tripped at once. I got the codes reset and ran some gumout injector or fuel cleaner through on the next fill-up but the codes tripped again a day or two later.