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Dreaded Code P0430

100K views 36 replies 21 participants last post by  julio 
#1 ·
Bought my '05 X new in Feb 2006, and from time to time over the last 3-4 years the SES light pops on after a fuel fill, particularly when filling with the engine running. Seems to be a common issue with X's - no big deal as the SES light normally goes off after a day or so.

A few months back, the SES came on after fueling - but this time did not go off. This caused my truck to fail MASS state inspection, and the guy cleared the light. Said drive it 100+ miles and then we can re-test. The light stayed off, until I refueled. WTF.

So, I took the vehicle to several places, all of which ran an OBD II scan, which came back with a P0430 code. According to a poster here, this code means "TW Catalyst SYS-B2"

Here is what each place said:

1. Advanced Auto - the Bank 2 oxygen sensor is bad. $100.44 for part.

2. Monroe Muffler - the Bank 2 Cat is bad. $1,015 installed. Ouch.

3. AutoZone - they gave me a print out that idenitfies 4 possibilities:
a. Large Vacuum leak
b. Fuel system fault
c. Ignition system failure
d. Failed Bank 2 catalytci converter

Now, since I am still in shock on the $1000+ bill for replacing the converter, I decided to just replace the gas cap and drive the truck for a few days to see whether the SES light goes off. I had a 2001 Jetta, which I purchased new, which also had an SES problem. Dealer wanted $600 just to drop the gas tank to see whether the sending unit was bad. New gas cap solved the problem and the light never came on again over more than 200,000 miles.

But, in case I am not lucky this way again, wondering whether anyone has had this issue and if so, how did you resolve it?

Seems like ignition system failure could relate to spark plugs, which I have not replaced and have 120,000+ miles on the originals. Probably should do that.

Additionally, I am getting about 14 miles to the gallon, instead of the normal 18-21 mpg.

Really hate to replace anything if it does not solve the issue. However, if the cat is bad, and not replaced, couldn't it damage the two cats behind it?
 
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#4 ·
Rockauto has both primary and secondary cats for a little over $300 for both. Nissan is not the only place you can get the cats, unless you live in CA.

You could play it safe and try the O2 sensor first and then get the cat(s) if that doesn't fix it. Then you are only out $100 (or less) if that's not it.
 
#5 ·
Heres what you do in mass.... Go get a bottle of techtron (sp) fuel cleaner, the stuff you put in the tank, and put it in the tank. Fill her up, clear the code ( there's a how to here to do that). Drive around for about 200 miles to guarrantee OBDii readyness, and then pass your inspection ( the light should still be off). Then work on gettin that thing replaced. Rockauto has them cheap and it cost me about 200 bucks to get it installed. Where are you in mass btw?
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#9 ·
What does the techtron do? I was told by my mechanic not to use fuel additives as they can over time ruin the cat. I did find a garage in Worcester that would do the work at 2 hours x $80 for $160 for labor. Not bad. They are going to order the cat from aftermarket provider.

The aftermarket cats are not good in CA, where I used to live, because they are made from a thinner metal than the Nissan parts, and thus they will not pass emmissions. Some mechanics will tell you that this thinner metal is also the reason aftermarkey cats may not last as long.

I read somewhere on this board that sometimes the aftermarket cats cause problems with the O2 sensors? Anybody know anything bout this??
 
#6 · (Edited)
I never heard of restrictions buying auto parts in California. I buy my parts on-line and the only thing I've bought from the dealer for either of my two Nissans was a locking lug key. California doesn't do inspections. They do test the pollution after 5 years and then every other year after than. Lots of other states do annual inspections, that's just silly!
 
#11 ·
Should have been more clear, I actualy purchased a Nissan one and had it installed; however that was before I did any research and went in blind as a necessity to pass the mass inspection. It cost me 200 bucks to get that installed. Alot of people are running the ones from rock on this site and those come with I believe a 50k mile warranty. As for the tectron, it changes the combustion slightly to trick the sensors. I wouldn't recommend constantly doing it but I would recommend doing what you can to pass that inspection because if it fails in mass, you need to get the entire system inspected at stupid money. Also it needs to be repaired at one of the state emissions facilities...
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#12 ·
#14 ·
ok reviving an old thread here for a minute.

My buddy stopped by and asked me to check what code he was throwing. He owns a 06 X, OR, has had the IPDM, and the FSU replaced with in the last 6 months and now has code P0430 ( catalytic converter bank 2 low) no other codes where triggered. just want to confirm that his drivers side Cats are finished or would there be any other reasons for this code to come up ? anything else I could help him check before he forks out for new cats???
 
#15 ·
yeah go to www.bigdaddiesgarage.com and buy the straight downstream O2 extenders for $15 and install. These move the O2 sensor out of the exhaust stream and wont trigger the light anymore for that cat. Or buy 2 and do both cats. I put about 20 of these on a yr without any returning lights.
 
#18 ·
yeah go to www.bigdaddiesgarage.com and buy the straight downstream O2 extenders for $15 and install. These move the O2 sensor out of the exhaust stream and wont trigger the light anymore for that cat. Or buy 2 and do both cats. I put about 20 of these on a yr without any returning lights.
Thanks Brutal,
I'm picking a couple of these for just insurance. Cheap price to pay.

P.S. You doing GoneMoab this year?
 
#17 ·
You can probobly get locally as they originally started life as spark plug anti oil foulers to move the plug tip out of the chamber for high oil consumption engines/cylinders. I like the fixed as designed too, but i also like to keep stupid money in my pocket too or use it in other areas
 
#19 ·
No Terry, not this yr, just making trophys this yr for Gone and shipping them out, next yr yes. Besides this yr im going to be spending some big change on a 40x60 shop with lift so i can play with my toys at home instead of work
 
#24 ·
@ AZ-Ted - Can you hook a brother up with the part numbers you bought? I just want to make sure I'm getting the right parts.

@ Anyone - Do you really need to replace both? I read that the sensor is after the first cat so just replacing that one should fix the code, right? Thoughts?
 
#30 ·
Well, had the X towed to a local shop this morning because I did not want to start it up as it was bogging down when I last drove it.
Here's the rundown: Had the PO430 code for 4 months, but kept driving it. Became worried when i couldnt go anywhere under 2500rpms so I attempted to replace the driver's primary cat in my driveway yesterday. Even with a propane torch, it wasn't happening since those bolts were rusted on. Got it to the shop since I wasn't risking further damage, and most of the time was spent taking the exhaust manifold heat shield off. Took all of 5 minutes to get the cat bolts off with an oxyacetaline torch. Had to unbolt the exhaust from the secondary cat just to slide it back enough to get the prinary cat out. Good time to check the secondary also. Now I have to replace that flange gasket, but it shouldn 't be a big deal. Honestly, just take it to a shop if you look under there and just see rust covered bolts.
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#32 ·
I've had the same code: P0430 for about 11 months, no noticeable performance issues. I live close to the NJ border so I ran over for some cheap gas and they didn't have anything but premium (93). I was pretty much empty so I had to put some in (put in 10 gallons). Drove 150 miles, and filled up with 87 in NY (gone another 300), light went out after the 60 mile mark with the NJ gas. Anything different with NJ gas?
 
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