Failed Smog, need opinions

[pcleary1210]

I'm going to try to skip making everyone read a lot of BS. Here's the skinny:
*NOx was gross polluter. HC's were a little bit high. CO was very good.
*225k, not the factory cat.
*Just installed a new bosch upstream O2 sensor, NGK plugs, K&N Air filter, oil/oil filter
*Sprayed out the MAF w/ cleaner
*Just removed ISR Mod and went back to traditional intake
*Old plugs were ok, just a little ashy, kinda white. Looked maybe to be running lean?
*Running a deckplate mod without the cap in.


Theories:
*Fuel Filter making it run lean. No idea when it was replaced last.
*Bosch sensor sucks, need to get a Denso for the front, move the Bosch to the back (it says it's upstream OR downstream)
*K&N fouled the MAF almost instantly. Need to clean again
*Need to give it more time to adjust to having fresh components. I only drove it like 20 miles before taking it in for smog. Reset ECU and go 100 miles.
*Time to seafoam the crap out of it.
*Deckplate mod letting too much air in? Fuel can't keep up?



Any other ideas, guys? We don't have an EGR if I recall. Coolant Temp Sensor maybe?

 

[vipergrhd]

Cat. converter

How old is your aftermarket Cat.? most aftermarket Cat.are only good 5-6 years in my experience.just go get another converter and run the test again.

 

[19963.4lsr5]

What are your "long term fuel trims"?

If your running lean those numbers will be high. Like towards 20% -10 to+10 is pretty normal.

Does your engine idle down to 650 or so? A vacuum leak can cause high nox but you'd expect a high idle to go with it.

I'm not a fan of Bosch O2 sensors. OEM, NTK, or DENSO for me.

 

[jeff88]

If your NOx is high and your plugs have the white ash typical of a lean condition, then I would guess it's the O2 sensor. I wouldn't even move it to the back, just get rid of it. As others have said, Bosch sucks, at least for Japanese cars.

I don't think the ISR is going to help or hurt in this situation, unless you had a block in the fuel line. The ECU is going to adjust based on what it sees, so unless you have a bad fuel filter/pump or bad injectors, I wouldn't worry about the ISR so much as your sensors.

Long story short, throw away/sell the Bosch O2 sensor, throw away/sell the K&N and clean the MAF. Maybe replace the spark plugs to ensure proper burn. If you still have a problem, then I would start looking at fuel line components.

Cal emissions?

 

[the great him]

i would seafoam the truck, buy a OE air filter -not a fan of K&Ns.... replace the cat and the bosch o2 for a denso o2 and run the tank almost empty, then fill it with premium(91/92 octane) and get a good drive cycle in, 80+miles before you go test it again.

-also reset the ECU after doing that work -pull the EFI fuse for 10min to clear the system

 

[the great him]

and seafoam before you replace the cat and the o2....

 

[jeff88]

Is it really necessary to pull the cat? It seems to not be an issue, so why go through the hassle? Unless the aftermarket cat has been on for most of the 225k.

You may even consider throwing in a bottle of techron with the premium, just to be safe.

If you're going to replace any sensors, you should just unplug the battery from the beginning. That way there is no chance of a short and by the time you're done, you know it has reset.

 

[FROGrunner]

i would seafoam the truck, buy a OE air filter -not a fan of K&Ns.... replace the cat and the bosch o2 for a denso o2 and run the tank almost empty, then fill it with premium(91/92 octane) and get a good drive cycle in, 80+miles before you go test it again.

-also reset the ECU after doing that work -pull the EFI fuse for 10min to clear the system

Please explain how running premium will help pass smog...it takes our ECU's approx 2-3 tanks to compensate for change in octane... if it were me i would never run bosch 02 sensors on a toyota...ever. You can take a rubber mallet and tap the cat itself to see if it rattles indicating broken cat pieces internally. Clean your MAF with some CRC MAF cleaner, then reset your EFI fuses/relay.

 

[the great him]

higher octain burns cleaner and better... im not saying he will see better performance, but it will burn cleaner, and i would not be worried about the cat internals being broken, just plugged, a lot of aftermarket cats use cheap internals and the quality of the platnum can be lower, thus melting or deforming and causing restrictions or just lacking in ability to thoroughly burn the gases.

 

[02SE]

FWIW, octane rating refers solely to the anti-knock properties of the gasoline. Regular and Premium grades burn equally clean. By Federal regulation, all grades of gasoline are required to have detergent additives.

Paying a Premium for High Octane Gasoline? | Consumer Information

 

[19963.4lsr5]

The O2 sensor is the final checks and ballances for the fuel system..If the sensor is lieing to the PCM it has no clue its running lean.

How old is your PCV?

 

[jeff88]

... i would not be worried about the cat internals being broken, just plugged...

If the cat was plugged, wouldn't he be noticing a rough drive? Bad idle, bad acceleration, etc.

I have a friend who had a Saturn where the internals of the cat became dislodged and depending on which way the stuff was turned, it caused terrible acceleration and rough idle. Conversely, if it was turned just right, where it allowed exhaust to flow, the car ran fine. He had good days and bad, depending on how the stuff was facing.

 

[the great him]

your talking about a severely melted cat and again a broken cat... but if the cat has just lost its ability to clean(a lot of aftermarket cats use cheap inferior parts, then you would notice no driveablity issues like that. i guess when i said melted i used the wrong term, burned out, is what i should have said

 

[FROGrunner]

higher octain burns cleaner and better... im not saying he will see better performance, but it will burn cleaner, and i would not be worried about the cat internals being broken, just plugged, a lot of aftermarket cats use cheap internals and the quality of the platnum can be lower, thus melting or deforming and causing restrictions or just lacking in ability to thoroughly burn the gases.

Im still confused with where youre getting your information... higher octane fuel only burns at a cooler rate, not a 'cleaner" rate...i work at a shop and we see broken cat internals on a regular basis...also a catalytic convertor doesn't burn the gases as they escape... the platinum attracts hydrocarbons to stick to the "honeycomb" inside the cat, therefore reducing the Hc's coming from the car...:ybrick:

 

[FROGrunner]

If the cat was plugged, wouldn't he be noticing a rough drive? Bad idle, bad acceleration, etc.

I have a friend who had a Saturn where the internals of the cat became dislodged and depending on which way the stuff was turned, it caused terrible acceleration and rough idle. Conversely, if it was turned just right, where it allowed exhaust to flow, the car ran fine. He had good days and bad, depending on how the stuff was facing.

yes he would notice a pretty big difference in the way the truck runs.

 

[the great him]

Im still confused with where youre getting your information... higher octane fuel only burns at a cooler rate, not a 'cleaner" rate...i work at a shop and we see broken cat internals on a regular basis...also a catalytic convertor doesn't burn the gases as they escape... the platinum attracts hydrocarbons to stick to the "honeycomb" inside the cat, therefore reducing the Hc's coming from the car...:ybrick:

you obviously have no clue how they work, so here, read up on them...

Catalytic converter - Wikipedia, the free encyclopedia
HowStuffWorks "What is a catalytic converter and how does it work?"
HowStuffWorks "How Catalytic Converters Work"
^^^ that one is really good at explaining it


to the OP;
<iframe width="560" height="315" src="//www.youtube.com/embed/DXchXMVteyk" frameborder="0" allowfullscreen></iframe>
take the advice here, you will need to find the root issue going on here...

 

[FROGrunner]

you obviously have no clue how they work, so here, read up on them...

Catalytic converter - Wikipedia, the free encyclopedia
HowStuffWorks "What is a catalytic converter and how does it work?"
HowStuffWorks "How Catalytic Converters Work"
^^^ that one is really good at explaining it


Interesting coming from someone who has zero idea how fuel burns or works...
None of those links back your idea on how a catalytic converter works.

 

[the great him]

maybe you need to read through that last link i posted... all of it. read the parts where it talks about reburning the gasses, and how newer cares are experimenting with preheated cats.... to help speed up the warm up time... or how moving the cat closer to the engine may help it be more effective...

higher octane fuel is more refined, by its nature that is true, i burns cleaner, leaves less deposits ect. and yes it provides the ability to make more power... if you dont believe me cool. but i encurage you to a second opinion say like a machine that actually does the tests. take the same vehicle and run it with the two different grades of fuel and see what you get in results in the detailed reports.


im not gonna argue with you, i know how the system works. youre not the only person here who works in a shop or who has worked in a shop...

 

[FROGrunner]

maybe you need to read through that last link i posted... all of it. read the parts where it talks about reburning the gasses, and how newer cares are experimenting with preheated cats.... to help speed up the warm up time... or how moving the cat closer to the engine may help it be more effective...

higher octane fuel is more refined, by its nature that is true, i burns cleaner, leaves less deposits ect. and yes it provides the ability to make more power... if you dont believe me cool. but i encurage you to a second opinion say like a machine that actually does the tests. take the same vehicle and run it with the two different grades of fuel and see what you get in results in the detailed reports.


im not gonna argue with you, i know how the system works. youre not the only person here who works in a shop or who has worked in a shop...

Funny you should mention that..we have a dyno here and have done numerous tests on fuel qualities/emissions. What we found is that unless the vehicle is properly tuned for higher octane fuel i.e force inducted or higher compression, you actually lose power and fuel economy. So like i said you don't necessarily get a cleaner burn, you get a cooler burn. Now on our legends race car, which has a high compression yamaha 1250 sport bike motor, we run 100 octane and actually gained power. As our dyno tech would say "To make the most amount of power, you want to run the lowest octane you can before encountering knock/detonation."



Octane rating - Wikipedia, the free encyclopedia

 

[02SE]

Now on our legends race car, which has a high compression yamaha 1250 sport bike motor,

The Legends Cars are cool. I had a '93 FJ1200, years ago. One of the few bikes I regret selling.

Not a pic of my bike, but it looked exactly like this.