Catalytic converters gone bad
12-09-2008, 06:09 AM
#11
Audiworld Junior Member
Join Date: Oct 2006
Posts: 650
Likes: 0
Received 0 Likes
on
0 Posts
I'm not familiar with MA smog laws, but... srsly, go look....
...for aftermarket units(if of course your cats are really garbage). Your mechanic is right about the price, but why pay so much.
12-09-2008, 06:20 AM
#12
AudiWorld Senior Member
Join Date: Apr 2008
Posts: 687
Likes: 0
Received 0 Likes
on
0 Posts
Your waiver threshold is definitely not $2700, so I'd think twice if I were you
<a href="http://massvehiclecheck.state.ma.us/motorist_whatiffail.html#waivers">Emissions Waivers</a><ul><li><a href="http://www.mass.gov/rmv/rmvnews/2008/factsheet.pdf">Massachusetts Vehicle Inspection Program Fact Sheet</a></li></ul>
12-09-2008, 06:50 AM
#15
Junior Member
Join Date: Jan 2007
Posts: 543
Likes: 0
Received 0 Likes
on
0 Posts
LOL! freakness you're the only one who's thinking anything... lol suger plums!
Although I wonder how he made it through H.S. with a name
like that.
"With a name like Dick Shine Racing, we have to be good!"
it's like the Schmuckers commercial...
like that.
"With a name like Dick Shine Racing, we have to be good!"
it's like the Schmuckers commercial...
12-09-2008, 07:17 AM
#18
AudiWorld Senior Member
Join Date: Apr 2008
Posts: 687
Likes: 0
Received 0 Likes
on
0 Posts
Yes---there is more to look at though
The TBS mentioned earlier is one thing to check with your dealer about (Audi set the the threshold too tight in the ECU, they have a memory flash to fix it if that applies to you).
Also, I would definitely clear the code and try to set readiness using the script in VAG-COM & VCDS, and if it passes everything, immediately bring it in for re-inspection. The codes you have now may be an isolated incident from long ago where the cat got tested by the ECU before it was sufficiently heated up (catalytic converters dont work when cold), which can happen if you do a lot of cold starts and the ECU sees the engine is warm but the cat is not.
Here are some write-ups on explaining what it could be besides the cat itself. Changing the cat is the last thing to do.
<a href="http://www.obd-codes.com/p0421">16805/P0421</a>
<a href="http://www.obd-codes.com/p0431">16815/P0431</a>
Also, I would definitely clear the code and try to set readiness using the script in VAG-COM & VCDS, and if it passes everything, immediately bring it in for re-inspection. The codes you have now may be an isolated incident from long ago where the cat got tested by the ECU before it was sufficiently heated up (catalytic converters dont work when cold), which can happen if you do a lot of cold starts and the ECU sees the engine is warm but the cat is not.
Here are some write-ups on explaining what it could be besides the cat itself. Changing the cat is the last thing to do.
<a href="http://www.obd-codes.com/p0421">16805/P0421</a>
<a href="http://www.obd-codes.com/p0431">16815/P0431</a>
12-09-2008, 07:39 AM
#19
New Member
Thread Starter
Join Date: Dec 2008
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
Re: Yes---there is more to look at though
My Mechanic has done that several times with his equipment and another garage's equipment. Last year he replaced the O2 sensor on Bank 1 and got the car inspected, the check engine light stayed off for a month or 2. Now it's back, but for both banks.
Pre-inspection, initially he got PO420 and PO430. He cleared the codes and I drove the car for a long trip, the light came on around 160 miles. The new codes were also PO420 and PO430. He cleared the codes again and I did my usual city driving and the light came in under 50 miles.
The codes I gave earlier were from the inspection station.
Pre-inspection, initially he got PO420 and PO430. He cleared the codes and I drove the car for a long trip, the light came on around 160 miles. The new codes were also PO420 and PO430. He cleared the codes again and I did my usual city driving and the light came in under 50 miles.
The codes I gave earlier were from the inspection station.
12-09-2008, 08:20 AM
#20
AudiWorld Senior Member
Join Date: Apr 2008
Posts: 687
Likes: 0
Received 0 Likes
on
0 Posts
You can set readiness with 0 miles of driving using VAG-COM
If I were you, I'd just clear everything, set readiness if you can, pass re-inspection if so, and then go somewhere else Audi/VW specific to look into why the CEL is going on, and if it is actually the cat, why did both cats go bad? You must fix the root cause or this is going to keep coming back and getting more expensive.
Also, there are 4 O2 sensors in the car, 2 on each bank, one before the cat and one after the cat. The post-cat O2 sensor is how the ECU determines how well the cat is working (it looks for the difference in O2 level between the pre-cat and post-cat sensor, expecting a minimum threshold to be met). Most likely he only changed the pre-cat sensor, but the post-cat O2 sensor could also have be going bad by now and this is the kind fault code you are getting first.
Last, we ask again, call the dealer service department to see if your car is eligible for the ECU flash for catalytic threshold. That could be all the problem really is.
Also, there are 4 O2 sensors in the car, 2 on each bank, one before the cat and one after the cat. The post-cat O2 sensor is how the ECU determines how well the cat is working (it looks for the difference in O2 level between the pre-cat and post-cat sensor, expecting a minimum threshold to be met). Most likely he only changed the pre-cat sensor, but the post-cat O2 sensor could also have be going bad by now and this is the kind fault code you are getting first.
Last, we ask again, call the dealer service department to see if your car is eligible for the ECU flash for catalytic threshold. That could be all the problem really is.