Failed emissions help please

5280nrg

New member
Just failed emissions: 4.298 on NOx GPM and 18.498 on CO2 GPM. Of course like a dip**** I waited until the last day! The only change I did was to add a K&N filter and deck plate. The PO had emissions pass in June of this year.

I pulled code with OBD 2 an there is not a single one???

Any ideas? I have just cleaned the MAF and put a reg filter, in and resealed the air box hole. What else to do?
 
Register to hide this ad
Not sure what else to do. But might not be a bad idea to Seafoam it, it can't hurt I wouldn't think. Just make sure you give it a good run after the Seafoam before you take it back.
 
+1 to what has been said so far. I've also failed emissions before and later passed simply with a tune up, including the much-forgotten PCV valve. Give that a change while you're in there. You can also try some injector cleaner, Lubro Moly makes an excellent one I've had luck with in the past on my parent's Chevy 350.
 
I failed the Ontario test 2 weeks ago . All 3 high speed readings. HC was 33% over,co was over 2 x the limit and NO was almost 4X the limit. Changed plugs(weren't to bad) and put a new cat on. The HC was now less then 1/2 the limit,CO was 1/5 the limit and NO was 10% of the limit. passed no problem. If you have an after market cat like I did it is most likely the problem since these motors have no egr system.
 
Thanks for the replys everyone. I was out in the field today and could not respond earlier.

So the tune up things I have done since I bought the T4R two months ago:

New Toyota plugs, Sea Foam in the tank and intake 30 days ago, fuel filter, new air filter (K&N is gone as of this morning, and before the second failed test), cleaned the MAF with correct cleaner, cleaned the TB with TB Cleaner, closed up the deckplate mod, new oil change less than 500 miles ago.

I have a feeling that the CAT and/or the O2 sensors are the problem, but wouldn't they cause codes??? I had an OBD2 scan done and there were no codes present.
 
Check the simple/free/cheapest things first. Then go digging after that.

Fuel, spark, timing, Evap, and exhaust.
 
how long had you been driving it for before it was tested?

Exactly, I did repeated WOT runs on the way to the shop, and then let it run "because my battery was weak" trying to keep the cats hot enough to pass. I don't remember the numbers off the top of my head but I didn't have any wiggle room on a couple.
 
Again sorry for delay in response. It has been a very long week. The first test was about a 40 mph 2 mile drive to the testing center. Not smart. The second test was after I changed out the air filter and cleaned the MAF and drove the hell out of it on the highway. The CO almost passed, but the NOX was still about 4.2.

From what I have read, it looks like I need a new CAT, but since there are no codes, I am told the O2 Sensors should be fine.

Picking up some new (used but not rusted) pipes in the morning and will have to bite the bullet with a new CAT. My pipes are way to rusted to weld on.

I might try pulling the O2 sensors and cleaning them really good, as I think the Sea Foam thing may have fouled them.

Oh, and I had replaced the spark plugs after all the Sea Foam went thru the system.
 
So I picked up a complete exhaust from a 2000 runner up to the CAT pipe. The pipes are in good shape and it has a Toyota muffler that looks like a dealer replacement but is in very good shape and the one weld is very clean.

I have decided to bite the bullet and just get the OEM direct fit pipe and CAT that bolts right to the exhaust manifold and the muffler piping. Everything should bolt up.

One of the previous owners had used one of the garbage "universal" cats, but as the guy who got me the exhaust setup said, its way to small for the truck.

It sucks to have to shell out the money, but it should take care of the problems for at least a few years.

Thanks for the help everyone!
 
get a bottle of smog pass at the local auto store, get the worse gas you can get, clean your egr and pray.
 
LOL, everyone keeps telling me to do that, or add like 4 bottles of "Heat" fuel line dryer to a half of a tank of gass and it will pass. I went ahead and ordered the Walker Direct Fit Pipe and Cat unit. It was $320 at AutoZone.

I figure if it is working correctly, then the O2 Sensors will not be transmitting info to the ECU which I would imagine would make the fuel air ratio's to change. There is also that environmental thing as well..

I will say, that after a month of driving and about 700 miles after the Sea Foam thing, that the MPG has dropped from 19 to about 16, so I think it actually jacked up the CAT and/or the O2 sensors.

I will clean the sensors really well when I put the system together. Im just going to leave the Toyota muffler on there and forego the MagnaFlow 18"... which also means that I now have a brand new in the box for sale. ha ha.:sobbing:
 
seafoam is o2 safe last time i checked. cat, not so much. the general rule of smog. drive the truck in 2nd gear for about 30 mins get the cat hot as fuk then smog it. the stuff i was talking about is this
51svxwN7GpL._SL500_AA300_.jpg
 
Had similar problems when smogging my 4runner. Changed plugs/wires, pcv, oil etc. Cleaned all the normal stuff. Ran that CRC Guarenteed to Pass crap (didn't)BTW-I wasn't throwing any codes. Replaced cat w/universal walker brand. All was cool.
Honestly telling the smog place you have a weak battery so you want to keep the truck running while you wait is a good idea. These trucks have to be very warm to make sure the cat is working correctly. While we were waiting to test mine I was running the truck at 4k rpm to keep everything happy.
Josh
 
Thanks Josh,
The guy at the testing center said that sometimes the system gets a hardon for a specific vehicle and no matter what you do, it will fail??? Don't know if he was just bull****ting me or if he was just giving me the inside scoop. In Colorado, if a vehicle fails twice, they are required to do a full diagnostic to find out exactly what the problem is. This is not general public knowledge, nor will they ever tell you that freely. But the guy most likely felt bad for me as he is T4R fanatic. I was able to secure an appointment on Monday morning to have them inspect it.

I figure it's free, and what the hell, they may be able to find a hidden factor that would cost me money to find on my own; and could possible help the runner become more fuel efficient. Win Win.

So in the end, I will have a brand new Walker Direct fit CAT, a "new" exhaust system from manifold to tail pipe (my current one is rusting away) and it only cost me $370 for everything. Nobody wants to throw money away per se, but I feel like I come away pretty good. Used vehicles cost money, it is the reality. I can and have done most work in my own shop, so I know I have saved thousands so far with the help of all the awesome people on this forum!!!
 
i disagree with the diagnosis and wish they wouldn't throw parts at it. report back then... if it doesn't fix it, how old is the 02 sensor? NOx isnt going to be fixed (reduced a bit yes) by replacing the cat. That happens if the engine is too lean or advanced.

now in one post you said high CO2 another you said high CO. which one is it?

Who told you if it doesn't throw a code then its not the problem? that is completely false. it will only throw a code if it falls way out of its parameters... a lazy sensor could still read "right". in your case, it probably reads a rich condition so the computer is reducing fuel, causing it to run lean which will produce high NOx. a rich burning engine will show high HC and CO. I see no one paid attention to my last post.
 
i disagree with the diagnosis and wish they wouldn't throw parts at it. report back then... if it doesn't fix it, how old is the 02 sensor? NOx isnt going to be fixed (reduced a bit yes) by replacing the cat. That happens if the engine is too lean or advanced.

now in one post you said high CO2 another you said high CO. which one is it?

Who told you if it doesn't throw a code then its not the problem? that is completely false. it will only throw a code if it falls way out of its parameters... a lazy sensor could still read "right". in your case, it probably reads a rich condition so the computer is reducing fuel, causing it to run lean which will produce high NOx. a rich burning engine will show high HC and CO. I see no one paid attention to my last post.

Thanks Mike,
Sorry for the delay. I appreciate your sage advice... After pulling out the old exhaust completely, it was evident that there were many issues going on. The rear o2 sensor was broken at the base, the converter was rusted thru on the top side, the muffler - aka "raspy rattle container" was also rusted thru on top.

I bought the Walker Ultra Fit full pipe CAT. All I can say is that Walker is a piece of crap company with no business welding anything. Perfect fit??? I think not. Half of one collector was blocked off!!! Not wanting to reduce the flow by 50% on one bank, I ended up cutting the new one just after the o2 sensor plate (which had two posts that were not even close to being straight) I then clamped the front end to the old down pipe where I cut out the old CAT. Then replaced the remaining pipes and muffler with original Toyota pipes from another vehicle.

I bought a new rear Bosche o2 sensor last night and wrapped it all up. Dico'd the battery overnight and now its running like a champ. I will post the emissions test results later today, with some pictures.
 

Members online

Forum statistics

Threads
278,307
Messages
3,554,050
Members
248,016
Latest member
Advally Service

Trending content

Back
Top