Failed Emissions... so need help!!
Failed Emissions... so need help!!
I took my sisters 96 Accord to try do the inspection, but the car failed the emissions portion of the test. On the paper given to me it said something like replacing the Crankshaft Position Sensor and it said "Catalyst System Efficiency Below Threshold".
I was wondering what is the price range to replace a Crankshaft position sensor and a catalytic converter, and is a hard job to DIY. My uncle will be doing the repairs, but I don't want to ask him if it's a difficult job since I've asked him to do a lot lately. My uncle knows a lot about cars cause he use to be a mechanic at some dealerships, but now he's doing something else.
Thanks for the help!
I was wondering what is the price range to replace a Crankshaft position sensor and a catalytic converter, and is a hard job to DIY. My uncle will be doing the repairs, but I don't want to ask him if it's a difficult job since I've asked him to do a lot lately. My uncle knows a lot about cars cause he use to be a mechanic at some dealerships, but now he's doing something else.
Thanks for the help!
You probably don't have to replace the catalytic converter, if your running 87 octane bump up a grade and possibly get a fuel injection cleaner and it will probably take care of it. More often then not if its anything more then that its an O2 sensor then the cat.
The crankshaft positions sensor is probably pretty cheap and easy to get to, however, again it could be a false alarm. Most cars don't require much to trigger the light to come on for crankshaft position sensors. I'd suggest going to advanced auto or some place similar and have the light reset(the OBDII port is behind the ash tray on your car, just so the guy isn't going crazy trying to find it) and try driving it. If the light comes back on right away then you probably have to replace the crankshaft sensor(which you could price while you are at the parts store), if it doesn't come back on in under 100 miles(plus or minus a little) that is enough to reset all readiness monitors and have your car inspected. Most parts stores will check the OBDII light for free and for simple things like you've listed even offer suggestions of what it would take to fix it. But I wouldn't worry about it unless they came back on right away. I'd say 80% of the OBDII codes I pull from cars are just glitches, if a sensor see's improper voltage for a fraction of a second under the circumstances it will trigger the light.
Good luck
The crankshaft positions sensor is probably pretty cheap and easy to get to, however, again it could be a false alarm. Most cars don't require much to trigger the light to come on for crankshaft position sensors. I'd suggest going to advanced auto or some place similar and have the light reset(the OBDII port is behind the ash tray on your car, just so the guy isn't going crazy trying to find it) and try driving it. If the light comes back on right away then you probably have to replace the crankshaft sensor(which you could price while you are at the parts store), if it doesn't come back on in under 100 miles(plus or minus a little) that is enough to reset all readiness monitors and have your car inspected. Most parts stores will check the OBDII light for free and for simple things like you've listed even offer suggestions of what it would take to fix it. But I wouldn't worry about it unless they came back on right away. I'd say 80% of the OBDII codes I pull from cars are just glitches, if a sensor see's improper voltage for a fraction of a second under the circumstances it will trigger the light.
Good luck
Thanks for the help! So most likely my uncle won't be able to do the catalytic coverter because of the welding involved? He does all his fixing at his house, but I don't think he's got tools for welding.
Originally Posted by HKD LA
Thanks for the help! So most likely my uncle won't be able to do the catalytic coverter because of the welding involved? He does all his fixing at his house, but I don't think he's got tools for welding.
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Originally Posted by Tireguy
No need to weld a cat. in place, there are direct fits that can be unbolted and re-bolted to the factory flanges. In fact it would be a very bad idea to weld it in place, most honda's use a donut style gasket on at least one end of there cat. this offers a bit of flex. But as I mentioned replacing the cat. is probably not that problem and would be a waste of money. I have been in the biz for a long time now and have a decent idea what I am talking about. Get the codes cleared and drive the car and see if they come back on before you just start replacing things. I've NEVER seen a case where catalyst effiecency below threshold code was corrected by replacing the cat. Run higher grade gas, possibly get a fuel injection cleaning done, if at all possible take the O2 sensors out and clean the carbon off them.


actually you can weld in the cat while still retaining the flexability of the gasket. you dont even have to cut out the gaskets when using a universal cat. the direct fit cats run about 100 bucks more than the universal. if you do need a cat just weld it in.
Originally Posted by subinf
actually you can weld in the cat while still retaining the flexability of the gasket. you dont even have to cut out the gaskets when using a universal cat. the direct fit cats run about 100 bucks more than the universal. if you do need a cat just weld it in.
Originally Posted by Tireguy
The problem with that in my area, is the flanges are the part that rot away first on cat's. So I guess it would really depend where you live, if your car isn't bombarded with salt every year it would be a different ball game. I've lived up here my whole life, sometimes I forget some folks don't have to deal with rust the way we do up here.
Ok, I'm thinking about follow your advice tireguy, but the only thing I'm afraid of is failing emmissions again. In NC inspection cost 30 bucks, and because I failed it they charged me 24 bucks for failing emissions, but when I get everything fixed and bring it back within 30 days they will inspect it and take $6 dollars so that in the end they still end up only taking $30 from me. What happens if i fail the second time? do I pay another $24 for failing it?
Originally Posted by subinf
that would mean that welding the cat in would make more sense. unbolting a rusted flange usually results in breaking the bolts...often its much easier to either reconstruct the flange from new pieces or taking a hit and just cutting out the rusted flange.
That's not how to deal with rust, yes bolts will break but they are easy to replace. You can not weld to a rotted flange, it just won't work. Typically the flanges on the cat. are weaker then those on the down pipe and are often where the leaks start up here. If a car is old enough to have a cat. failure due to rotting, its more then likely the cat. back part of the system has been replaced before so that comes apart fairly easy.
I also have to waranty a job when I do it at my place, so we don't cut corners because it just nips you(and the customer) in the ass down the road. In the north east welds are the FIRST thing to rust. From my over 10 years experience doing this it seems for every good welder, there are at least 100 bad welders. Any idiot can just weld shit together, but it will rot with in a year maybe two up here, if it holds together that long with out developing a leak. If you live in a climate that does not have to deal with rust, then sure take a chance welding it, but to save $100 now for the risk of potential problems down the road in the very short term is not a wise move.
Originally Posted by Tireguy
That's not how to deal with rust, yes bolts will break but they are easy to replace. You can not weld to a rotted flange, it just won't work. Typically the flanges on the cat. are weaker then those on the down pipe and are often where the leaks start up here. If a car is old enough to have a cat. failure due to rotting, its more then likely the cat. back part of the system has been replaced before so that comes apart fairly easy.
I also have to waranty a job when I do it at my place, so we don't cut corners because it just nips you(and the customer) in the ass down the road. In the north east welds are the FIRST thing to rust. From my over 10 years experience doing this it seems for every good welder, there are at least 100 bad welders. Any idiot can just weld shit together, but it will rot with in a year maybe two up here, if it holds together that long with out developing a leak. If you live in a climate that does not have to deal with rust, then sure take a chance welding it, but to save $100 now for the risk of potential problems down the road in the very short term is not a wise move.
I also have to waranty a job when I do it at my place, so we don't cut corners because it just nips you(and the customer) in the ass down the road. In the north east welds are the FIRST thing to rust. From my over 10 years experience doing this it seems for every good welder, there are at least 100 bad welders. Any idiot can just weld shit together, but it will rot with in a year maybe two up here, if it holds together that long with out developing a leak. If you live in a climate that does not have to deal with rust, then sure take a chance welding it, but to save $100 now for the risk of potential problems down the road in the very short term is not a wise move.

Originally Posted by subinf
Ok I missed the part about the flanges on the cat going first. I've been doing this for six years (yes not as long as you) and have seen plenty of cars from back east. I know that cutting the flanges off is the last resort, though usually the cars I come across have the flanges rotting together, not just one at a time.
I must admit I am envious of cars from your climate, I do a lot of alignments and every now and a again I get a car from the west coast, and it is a joy to do. Its amazing how various parts of the country attack cars in there own ways.
Originally Posted by Tireguy
No problem
I must admit I am envious of cars from your climate, I do a lot of alignments and every now and a again I get a car from the west coast, and it is a joy to do. Its amazing how various parts of the country attack cars in there own ways.
I must admit I am envious of cars from your climate, I do a lot of alignments and every now and a again I get a car from the west coast, and it is a joy to do. Its amazing how various parts of the country attack cars in there own ways.
no kidding. we had a car out from vermont the other month that needed its entire exhaust system replaced...the deterioration underneath was insane.
Yea the MIL was lit when I brought the car in, but they didn't say anything about the light. I don't really understand how the emissions portion of the inspection works. So do they just plug the thing into the car and then the car spits out the problems that the car has? So if I get the light reset, can I technically take it in for inspection and hope that the light doesn't relight and pass emmisions?
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