P0420- other things

[AlyAudi03]

So CEL popped on last night. Code is 16804 - Catalyst System; Bank 1: Efficiency Below Threshold
P0420 - 002 - Lower Limit Exceeded


Just wondering if there are any other possible causes for this code to be thrown. I'm in the process of starting my own business at the moment and a new cat is going to take from my start up money. Obviously this code is a bad cat, but is there anything else that could cause this code to be thrown that I should check out? o2 sensor could cause it but I read its rare. Any thoughts? Also, is it safe to drive until I can get this fixed? Thanks!

[SaabtoAudi]

Mine through the same code, shortly after installed my HFC. I put a spacer in and reset the code and it hasn't returned. If you are stock, and still have stock cat, it could mean that it is failing, and that's why you are getting the code.

[n7plus1]

time for a test pipe and some software.

[AlyAudi03]

can i drive it?? I have to be at work in 36 minutes, and need to know if I need to hitch a ride or if it is ok to drive it moderately until I can get it fixed?

[n7plus1]

meh, i wouldnt...i heard a clogged cat can cause other issues, IIRC.

[OMG_SHARK]

Click here.

[seanf86]

just cause its throwing the code doesnt mean its clogged, I'd drive it, I drove mine for 2 years like that before upgrading to 034 hfc, I put a spacer on my rear 02 just so I wouldn't have a cel. If you notice the car is lacking power then the cat is starting to clog and I'd look at getting it fixed promptly, if it drives fine I wouldn't worry too much

[AlyAudi03]

Well, it drives like crap. Is there anything I can do to clean it? Will that even do anything? I've heard conflicting opinions if seafoam. but if it, or anything else, will give me a couple more weeks until I can scrounge up $400 I'd be willing to try it. There is a lot of carbon in the tailpipes so I don't doubt it's clogged. Just don't want to have to cash in a savings bond to get the part by this weekend :/

[customa4]

$400 for whAt? You gonna do the install yourself? Just pick up an 034 HFC. It your cat is clogged I'm not sure there's much you can do with any cleaners to clear it up. People gut their cats but if you want to do it right the first time and not have to take the cat out again for a while, just go with 034. You might even be able to get some Audizine love if you PM them. They usually go for $295.

[AlyAudi03]

Yea I need new o2 sensors as well. They are old. So more like 400+. The 400+ was including the hfc. Either way 295 plus the spacer vs 400 isn't much of a difference. I'm still going to have to cash in a savings bond. FML!

[customa4]

Yea, guess I can't argue that... Looks like I tried to sugarcoat it.

[MrTurrtle]

testpipe would be tons cheaper. idk if your location does emissions testing but it would be cheaper!

[AlyAudi03]

Yea I noticed that but I live in Texas. There's enough smog blown in my face each day from all the big trucks. Don't want to contribute......I may see if I can find a used one cheap to hold me over. Just hope that one isn't messed up as well. Not really the route I want to take, but I already signed the lease for my suite and paid the deposit so holding off starting up my business isn't an option. So frustrated.

[customa4]

It is cheaper but it also smells like shit and doesn't break down any exhaust fumes.

[AlyAudi03]

what are some other good cat's that don't cost an arm and a leg, but do a decent job. I'm not to worried on better performance right now, but I don't want to order an aftermarket one that is going to crap out right away or cause other issues.....

[customa4]

I honestly think your best bet is used OEM or 034. Not too many proven other brands that will save you money that I've heard of.

[AlyAudi03]

Yea that's what I was scared of. Man this blows.

[customa4]

You throwing any other codes besides the P0420? Ross-Tech states that it could be a leak in the intake system. I believe I threw that code before when my turbo inlet pipe had a tear near the turbo. Did your car just all of a sudden lose performance or was it gradually over time?

[AlyAudi03]

kind of both, I had some other issues going on as well. We changed the cvt fluid thinking that was it, and it drove great, then it started acting up again around the same time we changed the valve cover gasket and cct gasket. Got progressively worse after that. I thought we had messed something up when getting the chain to tdc, but now I'm throwing this code. So i don't know. It's been off and on. It is possible I had a leak and something finally broke. We should look around and make sure something didn't indeed break or come loose. I had to work tonight otherwise we would have done that first thing. (we, being my father and I). I need to figure out what to do though, so i can try to get the parts by this weekend. It's driving, just really rough. It started not wanting to reverse out of my driveway about 2 weeks ago. You seriously have to mash the gas, because its up hill to get out. But it takes revving it really hard to get it to move.

it makes me wonder though, because we heard something break when we were fixing everything but we couldn't find what it was. Sounded like plastic so we figured it was probably a clip, because we couldn't see any obvious leaks. We may just need to take everything out and inspect it. Car idles so rough I highly doubt any other test is going to make a difference. I also just ordered a maf, because when I went to clean it it looked corroded. Would a bad maf throw this code? Obviously it can cause your fuel mixture to ruin it...but hey i've seen weirder things.

[AlyAudi03]

Well I guess it won't hurt to put the new maf in tomorrow and clear the dtc. See if that makes a difference, and go from there. May have to overnight a new cat if that's not it. Crap.

[n7plus1]

It is cheaper but it also smells like shit and doesn't break down any exhaust fumes.

i honestly think it smells better. testpipe ftw.

fuck, these are even CHEAPER now...wow...

http://www.ebay.com/itm/Audi-A4-B5-B...373bd5&vxp=mtr

pick that up. go get your ecu flashed and code the testpipe CEL out in the process. pass emissions...

seriously, if youre worried about "contributing" to smog, go get a prius...you are who jeremy clarkson warned me about.

[customa4]

Maybe Jeremy Clarkson doesn't have kids but I sure as hell don't want to contribute to my daughter inhaling that shit every day. What's a Prius have to do with it? Obviously if catalytic converters pass emissions testing they're efficient enough without being a Prius. I could care less what I'm contributing to the air as our air pollution is being screwed by plenty of other things that my car wouldn't have a huge affect. I do however care that I'm not killing my daughter every day at a stop light, ya know?