So 2 weeks ago the wonderful orange glow of the SES light appeared.

Autozone'ed it and it turns out to be P0430 - Catalyst System Efficiency Below Threshold (Bank 2).

I spoke with someone at a stealership, mechanic, and brain catts.

Stearship says bring it in.

Mechanic says replace the cat.

Brain says try o2 simulator.

I currently have a CALI-Spec Cattman Y (had it for over 40K). I did found many threads on this, but I am not sure how the Y pipe could help/ hurt the problem. Any insight will help.

I don't want to get into a trial and error situation if I don't have to.

 

I also have this problem and it's next on my do to list. Anyway, when the dealership tech diagnosed my coil problem he also mention that the P0430 problem was either the cat or the ECU. He suggested updating the firmware to the ECU before I replace the cat. I don't like the trial and error situation myself, but my plan is to get the update. If that doesn't work then I'll replace the cat myself and install a y-pipe and b-pipe at the same time. Hope this provides some help.

 

If you had a coil problem, that also could kick off a p0430.

 

Not sure of your miles, but even if under 8/80, the dealer won't do anything to a modified exhaust for free. Your other two options are feasible, but first make sure you have no exhaust system leaks. That could cause a p0430.

 

I had the same code. Dealer updated ECM software for free under 8/80k. That fixed the problem and it hasn't come back. I also have a 2000.

 

I got 162K+, so no dealership their.

I was just trying to pump the tech for some info.

I am glad I will be selling my maxima soon. Too many costly fixes and dealership only parts.

Should I just try replacing the O2?

 

If you have no other problems that can cause a p0430, it's most likely the cat. If you're selling the car, you need to think about how much a new owner cares about passing an emissions test.

 

Ooops. I made a mistake. The tech pulled P0430 for the coils and P0420 for the ECU/cat.

 

Those are both cat codes. p0420 is bank 1 and p0430 is bank 2. Not to say that a bad coil on bank 2 couldn't trigger a p0430. Do you remember which coil was bad? Did you replace all the coils?

 

i also have this problem with my 2000 maxima se and i replaced my cat, and also had the dealership update/reprogram my computer and that lasted for a few thousand miles and i also replaced all my o2 sensors and my SES light still comes on and i cant figure it out.

 

Is it still a p0430? If so, you're supposed to check for an exhaust leak before the cat, intake air leaks after the MAF, a bad injector or injector leak, faulty coil/spark plug (any oil on the plugs?), or bad timing. Basically something that's causing bad combustion or throwing off the mixture control system.

 

All coils were replaced to solve the rough engine idle. I didn't have a chance to test the coils to see which one was bad. I had the P0420 for a while now and sometimes the light would go on and off. Now it's back on and the engine idle is fine so now i know what I need to do next. But if I had a y-pipe like SixxOne, i'd try the o2 sim before messing with the other stuff.

 

^^^ I should have mentioned the MAF itself.

 

My idle is fine, and my car still drives very well. I replaced one coil once, but it was a very long time ago (2 1/2 years). It think I will check for leaks first, but I really do not think there is any leaks. The MAF was replaced when I put my Berk on like 35K miles ago.

 

I have this too, the light comes on and off once in a while but is staying on longer now... first time i checked it P0420 and recently that code was gone but it threw a P0430...!

Did the same thing, called the dealer and a mechanic, dealer said there IS a TSB to re-program but if its already been done I'm gonna need a "new front exhaust tube" and maybe cat. Which means BIG $$$$ so def. not getting it from them

 

Yeah if you can rule them out then you know it's something else. Just this morning while driving to work, I noticed the SES light was off. I'm not complaining, but it's just weird. Guarantee it will come back on before the end of the week.

 

The P0430 and P0420 codes will come and go over time until it gets to a point where the cat and/or O2 sensors are beyond intermittant faults.

For long-term replace the front pre-cat. But if you are selling the car shortly then either get and O2 simulator or just reset the ECU prior to selling it.

 

I hope you'll buy your next car with this kind of "extra feature" hidden....

 

I'm having problems with my 00 max I bought the car 500 miles ago 3 weeks or so, the ses light was on, they replace the 02 sensor, Light came back on after 60 miles replaced the cat on that bank now the light is back on again with the Code p1320 bad coil...I'm getting so fed up with this crap its not even funny. A friend of mine has an obd2 reader and it doesn't say which cyl is misfiring. The idle is fantastic... What should I do now, Scream and yell at the dealership I bought it from, they also went behind my back and got a sticker on the car after MA failed the original test, and had it retested at the same place we went originally. It's a cali Spec car, Hope this isn't your car foodmanry

 

I have an '01 SE manual and I had the p0430 code myself a month ago, and did a lot of research on this forum about it. I had the code reset by a friend, just for the heck of it, and within 10 miles it was back on... I have just over 100k miles on my car, figured it was a good gamble to replace the 02 sensors on the Bank 2 cat... I replaced both sensors, the one before and the one after the precat, cost me $60 each for bosch replacement...splicing them in is a pain b/c the connectors are SUPER SUCKY, but it did work out. I have over 500 miles on the car since the replacement and another reset of the codes (autozone this time) and no more yellow light! Figure 100k miles its a good bet to try replacing the sensors first before having someone else replace the cat (looks like a true pain to replace the cat...no thanks) though, the p0430 code can mean about 6-7 different things. $120 diy is not a bad gamble IMHO. hope this helps

 

Not my car...I still have my Max. Replacement of the pre-cat solved my P0430 issue and I haven't had an issue since I changed it out. That really is the long-term fix for this.

 

I brought the car to an Independent Shop and they replaced the o2 sensor again so far good but since then I had a p1320 code, Checked all the Coils and they are fine for now, Deleted the code with my obd2 scan tool and so far over 200 miles with no code..when the code comes back I'm going to change all the coils and the plugs while I'm at it. Try replacing your o2 sensor. Make sure you trust the guy who's doing it.

 

P0430 is the worst code ever to diagnosis. Under warranty, I had this code and they replaced the pre-cat, reprogrammed the ECU, and changed an O2 sensor.

Now, it's back. 126k on the car and I'm not wanting to spend much to get it to pass emissions testing here. Did the clear and drive for a while, but it is back for good now.

At least I have until end of March to get a band aid on this one.

 

I had the code a couple weeks ago. At the time I was driving the car nice. The weekend came and I had did some highway driving and went away. This is the first time this code came up for me. I am at 139K miles.

 

I have had this problem for the last 60K miles (162K currently). Comes and goes. Goes when I erase the code with the Actron scanner. Erased the code and then PASSED Pennsylvania inspection and emissions. The dealer and other mechanics tell me to replace hte Precat, but I do not want to drop the $700. Car runs exactly the same as it did before and have had not problems since. If this is bad for the long term please post why (I just dont know). Anyway, the scanner was $70 from amazon and works friggen great.

(http://www.amazon.com/Actron-CP9135-...4521831&sr=8-2)

 

Walmat has a junky scanner for about $30 that I use. It works for what I need and clears the codes.

I replaced the o2 sensors on the bank2 to see if that would fix the problem. So far so good, but it hasn't been very long.

 

I have this code currently as well but the car runs well. First got the code in november.. had it reset at autozone. a month later it came back.. i am just going to get an 02 simulator and go that route. Car runs and idles great, no smell, just not worth the $300-$400.00 for the pre-cat imho.

2000 infiniti

 

Post up which simulator you use and how it works bec I will have to go that route too. That code keeps on coming back even after reseting it.

 

Coils usually don't fail completely. You can try one of the two methods.
1) Wait for the occasion where you car is shaking, then plug in the reader (I repeat it will not work if your car stops misfiring), and try to pull up a P030X code. Sometimes I show up, sometimes it doesn't. If it doesnt, reset, and wait until it misfires again and try. Usually it will show up. The number X will be the cylinder number that's misfiring.
2) Get one front bank coil and one rear bank coil. Do it trial and error. one at a time.

I've only had to replace 3 of my coils. The other 3 have been fine.

 

Ive got the P0430 code bank2, stealerships are charging me almost 1200 to replace the cat. can someone please tell me which cat to replace, is it the main cat or the precat? i was thinking of just buying random cat and have it installed by a shop,thanks.

 

Do not replace cat!!!!! Don't pay for nothing!!! Go to o2 simulator.com buy the universal one for our car, its very easy to install and will get rid of the problem!!100% for sure get rid of the problem!!! PM me if u have questions!!

 

I have had the same code for 2 years, and I have not done anything about it. I also have not seen any drop in performance. It also passed Pennsylvania emissions and inspection (turned off code just prior to test). I have a Cali emissions car though, so I can't speak for the federal emissions. I thought about an o2 simulator, but did not see the need after I passed emissions. I can live with the code.

 

yep 02 simulator or you can drill out a spark plug spacer and place it between the sensor and the pipe for what they call a "ghetto sim"

Also, if I did anything to those cats, I would replace them with a straight pipe or clear them out

 

simulator is popular so that if a real code went off ud at least know! ya its just a little light, u could very easily just pull it out of the dash too, but its there for a reason, if your car trips and something that matters is wrong, trust me you'll be happy when it happens! It cost nearly nothing compared to having no light to tell u something is wrong!

But do what u want just dont cry when something goes cause u didn't have any light to let you know before! there are a lot more cods than cat does work bull****!

 

would any one suggest buying this front precat to solve the P0430?

It's an "EASTERN catalytic" PRECAT,
http://www.autopartswarehouse.com/de...EAST40387.html


or should i just opt for the OEM version...hence ill be giving Dave B a call

I dont want to do headers on my car which is why im pushing for the OEM replacement

 

I got a P0430 yesterday. The SES light has been coming off/on since I bought the car (Nov. 06). When I first plugged in the scanner back then it was P0011, but after it came on again yesterday and I plugged in, i got the P0430 (bank 2). I have a 2002 w/ 130,000 miles. O2 sensors or a bad cat with this many miles? I'm also in need of changing spark plugs if that would have any effect?
ANy ideas..?

 

^^according to the Nissan FSM, spark plugs could be related to the P0430

 

According the the FSM, the kitchen sink could be related to a P0430. Srsly.

 

hahaha. All these damn codes that people get w/ no sure-fix.. and all the other problems with these cars. Is it really worth it. Anyone wanna buy a clean '02 SE 6 speed on Tein coilovers??

So I should do the plugs and check coils for an outcome before attacking this code? Or is this just an excuse for me to get that cat-back exhuast that the car desparately needs?

 

Both my Maximas (4th & 5th gen) have ran tip top shape, never a problem with codes, etc. My 4th gen has a dying tranny, but after 13 year and 240k, I'll let it slide.


Not sure what you fellas do to your cars.

This is the only code, IMO, that is horrifically vague with too many fixes.

I'd say you have a MAF. A MAF will sometimes give you this code. A MAF will cause a lean condition, which will lead to damaged cats if the problem is not resolved in a timely manner, once gain, leading to this code.