That is a fantastic report you just wrote up. A pleasure to read.WrenchGremlin said:I got the P0420 code Catalyst system efficiency below threshold error at 134000 miles.
For anyone looking for a replacement, Code 420 indicates that its bank 1, which is the Right Hand side of the engine when standing on the drivers side looking towards the passenger side of the engine bay. For most people minds, this translates the the rear of the engine.
I'm replacing mine with an aftermarket cat from eastern. The best deal I could fine was for $263.73, sure beats the $750+ the stealer wanted to charge. You still have to get your own gaskets since they don't come with the replacement catalytic converter. Of course I'll install a new O2 sensor with it as well.
I found the price at http://www.import-catalytic-converter-warehouse.com
I also had a code P0327, which indicates the knock sensor voltage was low. I found the root cause was a short in the knock-sensor sub-harness that extends about the last 14" to the knock sensor. The replacement harness is $54 cost, but because I need it quickly, I paid the dealer price of $105. When I took the harness apart the wire is a coaxial style cable to shield the signal from spark plug coils. The cable has its outer shielding cut back and attached to a 2nd wire for the harness connector on both ends. When this was done the center wire jacket was nicked and over time had pulled back from the heat, exposing the center wire to the ground shielding - creating the short. The wire harness looks like it was made in a basement.
Since I have the intake manifold off, I decided to pull all the plugs and do a compression check. The low end was 192 PSI and the high side was 200 PSI with average about 195 PSI. Standard compression is 185 PSI. This is outstanding on an engine with 138,000 miles. The compression reading tells me that the valves are all seating properly and the piston rings are good.
BTW... this is the same engine the dealer told me I needed to replace.
Thanks Eric.Eric wrote:That is a fantastic report you just wrote up. A pleasure to read.
That is an interesting point. I find it annoying one has to remove the intake manifold to change the plugs but if thats what it takes, I'd rather do that than be forced to buy a new cat.WrenchGremlin said:
I think the reason the catalytic converter expired was that I waited a bit long (117K instead of 105K)to change the spark plugs and the gap became just to great to jump. The evidence was there as the plug was wet when I removed it. This in effect dumps raw fuel into the cat causing it to burn very hot and ulitmatly clogging it up. The driving effects are the same as fuel starvation. The car will hesitate and surge, you may even hear rattling when letting off the gas.
That's funny you should mention that... just last month my plates expired. I was able to pass the emissions inspection but only because my Nissan guy was able to work some magic and reset the SES light long enough to pass the test.Eric L. said:The struts is a safety issue and needs to be taken care of. As for the exhaust manifold, I assume there is a clogged catalyst in there or a bad O2 sensor. Both will affect gas mileage (esp since you drive 50,000 miles a year) so it may pay to get it fixed. You won't pass emissions for registration if the SES light is on.
$1K doesn't sound bad at all for struts AND an exhaust manifold. The dealer would probably get twice that. Also, needing those at 160K miles isn't bad either.FlyerNo9 said:I'm now at 160,000+ miles; the SES light is still on and now the right rear exhaust manifold and the struts need to be replaced [about $1000 at my local Nissan repair shop, not a dealer].