Breakin' [California smog test limits] 2: Electric Boogaloo.

[ksa8907]

Originally Posted by H-Man

I've noticed that my tailpipe is hotter now that I cleared out that substrate. I'll try to smog it tomorrow.

It could very well be that the restriction was causing really poor flow through the combustion chamber. The engine would require more power and thus fuel.

[H-Man]

I smogged the car today. Failed with 120 HC, 15% CO2, .2% CO, 670 NOX, and 0% oxygen. Still rich or lazy cat?

[2000mc]

Originally Posted by H-Man

Still rich or lazy cat?

Yes.
I would expect a new oem cat would return better results than one that has literally fallen apart. HOWEVER replacing a cat without resolving the cause for failure is an expensive road to go down.
I think I would want to drive the car with a scan tool and atleast monitor what the O2, and fuel trims are doing before getting serious about a cat.
I saw that the t-stat was replaced 16k ago, but didn't see what temperature it's running for you. (I've replaced the Stat in my Saturn twice, first replacement was down into the 170s after just a couple thousand miles, second one has been in there for probably 70k now)

[H-Man]

http://ecomodder.com/forum/showthrea...age-27192.html

You are in luck, I can actually pull data off of the ECU to figure out what I'm dealing with.

I suspect the cracked manifold (being replaced tomorrow), an extremely lazy oxygen sensor, and the PO running it without a thermostat contributed to the melted down precat, I'll find out more when I have a chance to run the TDCL datalogger.

[gone-ot]

Changing the catalytic converter BEFORE knowing WHY the engine is running TOO RICH is sorta akin to slapping on a larger bandage™ to a hemorrhaging artery and expecting things to immediately get better.

[H-Man]

Originally Posted by Old Tele man

Changing the catalytic converter BEFORE knowing WHY the engine is running TOO RICH is sorta akin to slapping on a larger bandage™ to a hemorrhaging artery and expecting things to immediately get better.

tl;dr My car has ran well enough that this is the first time I've had to do troubleshooting besides replacing an old oxygen sensor or plugging my MAP sensor back in, as such I don't know what I'm doing the way a grizzled veteran would.
That is why I'm waiting. I was asking if it was running rich or if the cat was old, I think that it is still running rich but I haven't looked at tailpipe emissions results enough to be able to tell the difference TBH. I have until November to pass smog, I smogged it as early as possible so that if I fail smog, I can fix the car at a slower, more affordable pace. I don't have much experience dealing with EFI, most of my time wrenching on emission controls was done on feedback carbs trying to get my dad's car to pass. I don't know much about fighting EFI systems.

[gone-ot]

Because the engine's ECM controls everything in EFI systems, begin looking at the sensors providing "input" signals INTO the computer, such as wheel-sensor, manifold air density, catalyst hi & low, coolant temp, etc.

Do you have an OBD reader? Something to tell you what the ECM thinks is wrong and thus causing too rich A/F operation?

[H-Man]

Originally Posted by Old Tele man

Because the engine's ECM controls everything in EFI systems, begin looking at the sensors providing "input" signals INTO the computer, such as wheel-sensor, manifold air density, catalyst hi & low, coolant temp, etc.

Do you have an OBD reader? Something to tell you what the ECM thinks is wrong and thus causing too rich A/F operation?

Yes and no. The ECU pretty much refuses to throw a code unless unplug something it can throw a code for, BUT I can watch live sensor data. See this thread: http://ecomodder.com/forum/showthrea...age-27192.html

I attached a datalog of what the ECU is outputting.

I'm using CarTester8000StableEdition_English, going to file-> view and viewing the .ctr extracted from the attached zip file.

PM me if you just want me to send you a dropbox link to the program.
OBD-1 Serial Interface - Toyota Wiki

[gone-ot]

Things that can make the ECM *think* the A/F mixture should be RICHER than normal:

1) Engine HOT, ie: high coolant temperature (sensor bad).
2) High engine LOAD, ie: high TORQUE loading (engine rpm does not match throttle position).
3) MAP sensor is dirty.
4) Front Cat-sensor bad, ie: ECM thinks cat isn't up to operating temperature yet.
5) Back Cat-sensor bad.
6) One (or more) fuel injector(s) partly stuck open.

[ksa8907]

Originally Posted by H-Man

I smogged the car today. Failed with 120 HC, 15% CO2, .2% CO, 670 NOX, and 0% oxygen. Still rich or lazy cat?

Unburned fuel has decreased, unburned oxygen is decreased, more carbon dioxide (more fuel being burned), less carbon (soot), nox is still high (this is actually good, it means the combustion temperature is nice and hot).

I would do a once over on the spark plug gap, make sure the coolant temp sensor is ineed working properly. Replace the cat.

Or... http://ecomodder.com/forum/showthrea...-do-23483.html