Advice on replacing catalytic converters
10-03-2015, 11:59 PM
#1
Junior Member
Thread Starter
Join Date: Dec 2006
Location: Attleboro, MA
Posts: 58
Advice on replacing catalytic converters
My 2003 Maxima SE has 152,500 miles, stock exhaust and recently I had a leak in my exhaust so I had to get it check out. Went to a local shop and asked for a quote as to what needs to be done. The small leak was patched and clamped for $80.
They showed me how my exhaust and catalytic converter looked which was bad since the front catalytic converter has a tiny hole and the exhaust is rotting out from being 12 yrs old. I was quoted $2,000
for front direct fit catalytic converter, y pipe, universal converter, oxygen sensor and labor.
I would need to pass emissions in few months, I live in Massachusetts.
What's my cheapest option for proper job and the estimated cost???
Thanks in advance!!
They showed me how my exhaust and catalytic converter looked which was bad since the front catalytic converter has a tiny hole and the exhaust is rotting out from being 12 yrs old. I was quoted $2,000
for front direct fit catalytic converter, y pipe, universal converter, oxygen sensor and labor.I would need to pass emissions in few months, I live in Massachusetts.
What's my cheapest option for proper job and the estimated cost???
Thanks in advance!!
10-04-2015, 02:41 AM
#2
Senior Member
Join Date: Feb 2009
Location: Columbia SC
Posts: 2,284
My 2003 Maxima SE has 152,500 miles, stock exhaust and recently I had a leak in my exhaust so I had to get it check out. Went to a local shop and asked for a quote as to what needs to be done. The small leak was patched and clamped for $80.
They showed me how my exhaust and catalytic converter looked which was bad since the front catalytic converter has a tiny hole and the exhaust is rotting out from being 12 yrs old. I was quoted $2,000 for front direct fit catalytic converter, y pipe, universal converter, oxygen sensor and labor.
I would need to pass emissions in few months, I live in Massachusetts.
What's my cheapest option for proper job and the estimated cost???
Thanks in advance!!
They showed me how my exhaust and catalytic converter looked which was bad since the front catalytic converter has a tiny hole and the exhaust is rotting out from being 12 yrs old. I was quoted $2,000
for front direct fit catalytic converter, y pipe, universal converter, oxygen sensor and labor.I would need to pass emissions in few months, I live in Massachusetts.
What's my cheapest option for proper job and the estimated cost???
Thanks in advance!!
10-04-2015, 04:04 AM
#4
Member
Join Date: May 2004
Posts: 279
Is the CEL on? If not, I believe MA only plugs into the OBDII to check for
any codes. If no codes, it will pass. I know here in Jersey, the car can go through
with exhaust leaks, no brakes, bald tires, etc but if it passes the "plug in"
test, as well as the gas cap test, it will pass inspection.
Once it passes, then you can take your time and decide in which direction to go.
Aftermarket cats usually have a short life and are not worth the effort and an 12
year old exhaust isn't going to look pretty. If it passes the "inspection", personally
I would just replace the exhaust after the main cat. Now, if the precat leak becomes
larger and a nuisance that would need to be addressed.
any codes. If no codes, it will pass. I know here in Jersey, the car can go through
with exhaust leaks, no brakes, bald tires, etc but if it passes the "plug in"
test, as well as the gas cap test, it will pass inspection.
Once it passes, then you can take your time and decide in which direction to go.
Aftermarket cats usually have a short life and are not worth the effort and an 12
year old exhaust isn't going to look pretty. If it passes the "inspection", personally
I would just replace the exhaust after the main cat. Now, if the precat leak becomes
larger and a nuisance that would need to be addressed.
10-04-2015, 06:44 PM
#6
You don't need the pre-cats to pass an emissions test unless they are checking the engine is cold and it is first started. That is when the pre-cats in the y-pipe play a part. The main cat doesn't work 100% when it is cold. But once the main cat warms up, you will pass an emissions test without have pre-cats.
10-04-2015, 08:21 PM
#7
Senior Member
Join Date: Jan 2003
Location: California
Posts: 1,445
You don't need the pre-cats to pass an emissions test unless they are checking the engine is cold and it is first started. That is when the pre-cats in the y-pipe play a part. The main cat doesn't work 100% when it is cold. But once the main cat warms up, you will pass an emissions test without have pre-cats.
I am in California, and to pass the test here, your car must satisfy all of the following three requirements:
- CEL light: Must NOT be on.
- OBDC check: No more the ONE monitor in an "incomplete" state.
- Exhaust Emission Check: Must pass the ***/NOx levels specified for CA.
10-04-2015, 08:50 PM
#8
^^OP, check your state laws first and then proceed. 2k$ is a lot to spend on repairs on these year maximas. Cali should be the most expensive as cats are usually made 49 state legal...leaving california to their own unique pricey parts. Good luck and report back 
10-04-2015, 10:22 PM
#9
Dennis, are you sure about this?
I am in California, and to pass the test here, your car must satisfy all of the following three requirements:
I am in California, and to pass the test here, your car must satisfy all of the following three requirements:
- CEL light: Must NOT be on.
- OBDC check: No more the ONE monitor in an "incomplete" state.
- Exhaust Emission Check: Must pass the ***/NOx levels specified for CA.
I had to look up my previous emissions test here. I thought we had to pass a tailpipe sniffer type test but the paper I get does not have any CO or NO numbers on them. I looked up the Texas testing requirements and OBD II cars do not get a tailpipe sniffer test. I had a 94 Maxima so I guess that is why it stuck in my head. The OBD testing here only allows one "Not Ready" to be able to pass and the gas cap is put in some kind of tester.
The 2014 & 2015 tests on my 2000 Maxima had the O2 sensor monitor as not ready, while earlier tests show it as ready. This may be because of having a Warpspeed y-pipe, but I kind of doubt it because the y-pipe has been on for 3 tests and only the last 2 have been not ready. The not ready is probably because I have a weak downstream sensor that keeps giving me a P0138 code every so often. I just had the code and reset it shortly before I had the car tested.
So I don't know about the CO & NO part. For one thing, my car is a Fed spec, not Cali, so even in 100% stock form my car might not pass the California test.
10-05-2015, 03:27 AM
#10
Member
Join Date: May 2004
Posts: 279
Think it would be virtually impossible for the car to pass with the precats removed as the rear or downstream O2 senors monitor the precat conditions, one before the precat and one after, so with the precat removed, the CEL would certainly come on.
Now if someone "modified" the exhaust to fool the ecu then it could pass.
Our '89TII we purchased new, naturally pre OBD port, has the precat removed
and still passes the sniffer test with a aftermarket Bonez high flow cat and the OE
air pipe functioning, but this car has only one O2 sensor to monitor mixture.
Now if someone "modified" the exhaust to fool the ecu then it could pass.
Our '89TII we purchased new, naturally pre OBD port, has the precat removed
and still passes the sniffer test with a aftermarket Bonez high flow cat and the OE
air pipe functioning, but this car has only one O2 sensor to monitor mixture.
Last edited by Turbonut; 10-05-2015 at 03:32 AM.
10-05-2015, 04:03 PM
#11
Ok let me set things straight...
1. New cal smog laws do not require sniffer test any longer. Only visual inspection and hook up with the OBDII. You can have up to one not ready on the monitoring.
2. Yes your car will pass emissions without precats but this is only if your main cat is working very well. OP install a non fouler and be done with it. I highly doubt the smog tech is going to climb under your car to see the non fouler.
Alternatively the OP could just reset the codes and monitor them until only one is not ready then go to smog place.
1. New cal smog laws do not require sniffer test any longer. Only visual inspection and hook up with the OBDII. You can have up to one not ready on the monitoring.
2. Yes your car will pass emissions without precats but this is only if your main cat is working very well. OP install a non fouler and be done with it. I highly doubt the smog tech is going to climb under your car to see the non fouler.
Alternatively the OP could just reset the codes and monitor them until only one is not ready then go to smog place.
Last edited by foodmanry; 10-06-2015 at 10:51 AM.
10-05-2015, 11:50 PM
#12
Think it would be virtually impossible for the car to pass with the precats removed as the rear or downstream O2 senors monitor the precat conditions, one before the precat and one after, so with the precat removed, the CEL would certainly come on.
Now if someone "modified" the exhaust to fool the ecu then it could pass.
Our '89TII we purchased new, naturally pre OBD port, has the precat removed
and still passes the sniffer test with a aftermarket Bonez high flow cat and the OE
air pipe functioning, but this car has only one O2 sensor to monitor mixture.
Now if someone "modified" the exhaust to fool the ecu then it could pass.
Our '89TII we purchased new, naturally pre OBD port, has the precat removed
and still passes the sniffer test with a aftermarket Bonez high flow cat and the OE
air pipe functioning, but this car has only one O2 sensor to monitor mixture.
12-12-2015, 04:30 AM
#14
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Join Date: Feb 2009
Location: Columbia SC
Posts: 2,284
12-12-2015, 09:39 AM
#15
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Join Date: Jan 2003
Location: California
Posts: 1,445
That's why I went OEM. It was expensive, but I came to the conclusion that I have no choice; read my story here: https://maxima.org/forums/5th-genera...ete-p0430.html . I did it because my car is in excellent shape otherwise and I want to keep it for a while.
My advice: Find out exactly what/how they test in your state. Don't rely on any 2nd-hand info: stop by a reputable test station and ask them directly, for the latest/newest test requirements.
Last edited by maxiiiboy; 12-12-2015 at 09:43 AM.
12-12-2015, 12:40 PM
#16
Senior Member
Join Date: Feb 2009
Location: Columbia SC
Posts: 2,284
What I have heard, and I heard it repeatedly, that the aftermarket converters don't last. They last, like 2 years. So they are good for one inspection.
That's why I went OEM. It was expensive, but I came to the conclusion that I have no choice; read my story here: https://maxima.org/forums/5th-genera...ete-p0430.html . I did it because my car is in excellent shape otherwise and I want to keep it for a while.
My advice: Find out exactly what/how they test in your state. Don't rely on any 2nd-hand info: stop by a reputable test station and ask them directly, for the latest/newest test requirements.
That's why I went OEM. It was expensive, but I came to the conclusion that I have no choice; read my story here: https://maxima.org/forums/5th-genera...ete-p0430.html . I did it because my car is in excellent shape otherwise and I want to keep it for a while.
My advice: Find out exactly what/how they test in your state. Don't rely on any 2nd-hand info: stop by a reputable test station and ask them directly, for the latest/newest test requirements.
12-12-2015, 04:34 PM
#17
If you live in a state without any testing, but headers or gut the pre-cats and call it a day. You could even run a test pipe and delete the main cat. If you don't have to worry about inspection then why worry about the cats know what I'm saying.
12-12-2015, 10:55 PM
#19
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Join Date: Feb 2009
Location: Columbia SC
Posts: 2,284
Well the only problem i have with gutting my pre cats is most of the bolts are rusty and im not really an exhaust man. I want to let a shop replace the b1 pre cat and replace the bolts on the b2 pre cat so if that one does start to fail, then I can gut both myself, as of right now the bolts at the y-pipe and b2 pre cat are rusted on.
12-13-2015, 02:41 PM
#20
Well the only problem i have with gutting my pre cats is most of the bolts are rusty and im not really an exhaust man. I want to let a shop replace the b1 pre cat and replace the bolts on the b2 pre cat so if that one does start to fail, then I can gut both myself, as of right now the bolts at the y-pipe and b2 pre cat are rusted on.
12-13-2015, 11:23 PM
#21
Senior Member
Join Date: Feb 2009
Location: Columbia SC
Posts: 2,284
If you're taking it to a shop have them remove and replace bolts just don't put a new one on. They're pretty pricey and most shops won't gut a cat. If you have them replace all the bolts then you can go back and gut them. Just my advice. Since you don't have inspection I would save the money.
12-14-2015, 05:39 AM
#22
If you're taking it to a shop have them remove and replace bolts just don't put a new one on. They're pretty pricey and most shops won't gut a cat. If you have them replace all the bolts then you can go back and gut them. Just my advice. Since you don't have inspection I would save the money.
12-14-2015, 12:02 PM
#23
Senior Member
Join Date: Feb 2009
Location: Columbia SC
Posts: 2,284
Kool great idea i will do that. I asked the guy at the shop about removing the cats altogather, he said id get 5mpg. I just laughed at that. But ill just let them replace the rusted bolts ect.
12-14-2015, 12:56 PM
#24
That's a red flag...or he is just saying that so you don't remove them. The cats will not affect your MPG. The primary O2's are the main factors for MPG.
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