Really strong exhaust fumes on my 100. (1 Viewer)

[1meancruiser]

Guys, my LC 100 Has really strong exhaust fumes at start up. it's really bothered my wife and 6 year, for sometime now, as she gets dropped off in the LC in the mornings. It's reflective more of a carbureted motor then a ULEV fuel injected Toyota. Does anyone else have this problem?

I'm thinking about replacing the catalytic converters with magna flow high flow cats. I know it seems contradictory but I think some new cats may be the answer. I had a bad fuel pump sometime back and I think that led to flooding of the engine and maybe some damage to the Cats as a result, although it hasn't thrown any codes.

Also, my gas mileage is really low. I drove 250 miles on Friday, all highway and got 12 miles to the gallon average. I'm giving serious consideration to adding a chip or having a tuner remap the fuel air ratio. Lean her out just a tad but still be richer than normal. From what I've heard, these 100s run exceptionally rich. Any feedback on this would be much appreciated?

thanks!

 

[arcteryx]

Whoa.... First, unless you are throwing a code, which you say it's not, I would not go and start replacing cats, that's 2+ grand for the pair. And non-OEM cats are junk, so you need to get OEM ones if you do that. And bad cats do not cause exhaust smells, leaks do. Second, take a look at your exhaust manifolds, this is a common failure and they can either have fractures and need to be replaced or maybe it needs new gaskets. Third, if your manifolds are good, I would take it to an exhaust shop and have them look at the gaskets at the flanges for the rest of the exhaust, unless you feel comfortable doing it.

 

[1meancruiser]

I wouldn't get factory cats. I was looking at magna flow which I've heard of pretty good for around $300 a pair, kind of surprised to hear all aftermarket cats are bad? I don't hear any exhaust leaks. Not from the exhaust manifold or the exhaust system. I will crawl underneath while the car is running and take a look around, I highly doubt there's a leak.

QUOTE="arcteryx, post: 10200483, member: 4381"]Whoa.... First, unless you are throwing a code, which you say it's not, I would not go and start replacing cats, that's 2+ grand for the pair. And non-OEM cats are junk, so you need to get OEM ones if you do that. And bad cats do not cause exhaust smells, leaks do. Second, take a look at your exhaust manifolds, this is a common failure and they can either have fractures and need to be replaced or maybe it needs new gaskets. Third, if your manifolds are good, I would take it to an exhaust shop and have them look at the gaskets at the flanges for the rest of the exhaust, unless you feel comfortable doing it.[/QUOTE]

 

[Sandroad]

I assume you mean fumes out the rear tailpipe and not from some other location. I'd clean the mass air flow sensor, replace oxygen sensors (4), clean the throttle body, replace the spark plugs, and replace the air filter and gas filter all before doing anything with the cats or tuner mapping. And, I see no evidence from the combustion chamber or anything downstream of that in my 4.7L which would indicate running rich. Where did you hear they run exceptionally rich?

 

[1meancruiser]

Good suggestions. Speaking to a Toyota technician along with various conversations, I've heard that part of the reason these engines last as long as they do is because they run rich.

I assume you mean fumes out the rear tailpipe and not from some other location. I'd clean the mass air flow sensor, replace oxygen sensors (4), clean the throttle body, replace the spark plugs, and replace the air filter and gas filter all before doing anything with the cats or tuner mapping. And, I see no evidence from the combustion chamber or anything downstream of that in my 4.7L which would indicate running rich. Where did you hear they run exceptionally rich?

 

[arcteryx]

Oh, you mean the smell out of your tailpipe? That is not how I read your first post, I interpreted that as fumes in the cabin. If it is the tailpipe, what sandroad said is good to start with. And I would still not get cats.

 

[highonpottery]

$300 is more like the labor to install the exhaust parts, lol. That's about what I paid for my Pickup and Corolla cat and they only have one each. I dunno which one our rig takes but magnaflow has two types that List for 100-series and one is $300, the other is $550. Remember we gotta pay a premium to get a special CA edition everything.

I'd try the baseline/tuneup suggested above before anything and see what that changes. I'd guess just o2 sensors would be a good improvement.

 

[1meancruiser]

It's most noticeable when the LC is in the garage, the tailpipe is facing out but the cabin does end up getting a lot of exhaust. I should have clarified earlier.

I think this is a good commonsense approach to it, taking care of some of the basic maintenance items and then working my way up. One question:

Does anyone know what the filter element, on the top portion of the air box, between the air filter and the mass airflow sensor is for?

Oh, you mean the smell out of your tailpipe? That is not how I read your first post, I interpreted that as fumes in the cabin. If it is the tailpipe, what sandroad said is good to start with. And I would still not get cats.

 

[Slickspawn]

That's the startup strategy to get the cats hot as quickly as possible. It is a stronger gas smell than some other brands I've had. After startup I don't notice it ever though.

 

[Julian Stead]

does it smell when the engine has warmed up. If only when cold then the oxy sensors or cats are not working then anyway.

 

[Julian Stead]

Ps. If changing the oxy sensors, then only the two before the cats alter the fuel strategy, the two after the cats just monitor the cat efficiency, so changing them wouldnt alter anything.

 

[2001LC]

Guys, my LC 100 Has really strong exhaust fumes at start up. it's really bothered my wife and 6 year, for sometime now, as she gets dropped off in the LC in the mornings. It's reflective more of a carbureted motor then a ULEV fuel injected Toyota. Does anyone else have this problem?

I'm thinking about replacing the catalytic converters with magna flow high flow cats. I know it seems contradictory but I think some new cats may be the answer. I had a bad fuel pump sometime back and I think that led to flooding of the engine and maybe some damage to the Cats as a result, although it hasn't thrown any codes.

Also, my gas mileage is really low. I drove 250 miles on Friday, all highway and got 12 miles to the gallon average. I'm giving serious consideration to adding a chip or having a tuner remap the fuel air ratio. Lean her out just a tad but still be richer than normal. From what I've heard, these 100s run exceptionally rich. Any feedback on this would be much appreciated?

thanks!

I get strong exhaust smell on warm up, which seem normal IMHO.

You MPG is low, but considering what I read on your 06 mods. You must consider weight addition and tire size. So has this changed with mods or is this something new?

If new do a complete tune-up, then have shop tested. 06-07 have added smog equipment (air pump IIRC)

If this has been the case since mods, get the wife and all stock daily driver and warm-up outside with windows up.

 

[wpsfan]

It's most noticeable when the LC is in the garage, the tailpipe is facing out but the cabin does end up getting a lot of exhaust. I should have clarified earlier.

My exhaust also faces out but when I start mine I immediately back the LC out of the garage and then let it warm up, if not fumes will float back into the garage pretty quick.

 

[benc]

It is normal to get the fumes on start up until the cats warm up, the cats will not burn the excess exhaust gasses until they warm up.
If you are warming it up in the garage make sure the door is open and it wouldn't hurt to back out a little.

 

[Julian Stead]

I double checked to see what year your LC is but couldnt find it. If you have a later model with a air pump then check the function of this, as this adds air into the exhaust to help burn off unburnt fuel during the cold start strategy, this also allows the CATS to warm up quicker. This turns off when the oxy sensors are closed loop(functioning). If you dont have a air pump then there isnt much you can do on cold start as emmisions are not monitored at this stage. The pump was fitted by toyota to reduce the emmisions at cold start to comply with emmision laws.

If your problem persists when the vehicle is hot then further investigation required, but I dont think new CATS would be your answer. Modern vehicles run lean not rich to comply with these strict emmision laws.

 

[tabraha]

Good suggestions. Speaking to a Toyota technician along with various conversations, I've heard that part of the reason these engines last as long as they do is because they run rich.

What's the source of the 2UZ-FE supposedly running rich? ULEV cert tends to contradict that. Mine have always been pretty light on the fumes when warm. I'd have the truck scanned as I believe the O2 sensors can throw a soft code that will not light up the dash but register as being marginal in performance. If your sig is up to date and you are at 60k then that would be a bit premature for O2 sensor failure; BUT ethanol is killing O2 sensors way earlier than conventional gas. Being an '06 Julian Stead's recommendation of checking the air pump is also worthwhile.

I believe 125k was when my O2 sensors started to die off. Extra stink and a drop in mileage are classic dead emission control symptoms as it will default to a rich scenario when an O2 sensor fails to give feedback. Cats are usually good to go unless you ride around with bad O2 sensors for a really, really long time. Both of my 100's are well past 200k and on original cats but replacement sensors.

 

[Julian Stead]

The fuel pump issue could of fouled up the oxy sensors prematurely, I would personally add a good quality fuel cleaner and a tank of good quality fuel and give the engine a blast up the highway and see if the problem persists, It doesn't cost much. What was wrong with the fuel pump to cause flooding, that is a strange fault in itself as the fuel rail normaly has a pressure regulator that returns excess fuel back to the tank, but without the facts it hard to comment on that. If you have techstream you can probably read the injection duration to find out if the engine is being told to run richer than normal when hot.

 

[Output Shaft]

Get a smog test. You'll find out right away if the cats are malfunctioning.

 

[1meancruiser]

Yeah I've heard that before, only change the oxygen sensors off the exhaust manifolds and not bother with the ones in the cats. With only 77,000 miles I didn't think I need to but I may give it a try after a tuneup.

 

[1meancruiser]

Some of the first 2006 to come out had the older fuel pumps which were insufficient for the newer cylinder heads. Mine was one of those. It was overheating on hotter days and longer drives. From what I recall, it caused the left cat to fail, the dealership replaced it but I had another episode after, only to realize the fuel pump was at fault, then replaced the fuel pump. However, when the left cat Failed, it showed a code and it was obvious that it had failed . This is not the case now, it is not throwing a code.

The fuel pump issue could of fouled up the oxy sensors prematurely, I would personally add a good quality fuel cleaner and a tank of good quality fuel and give the engine a blast up the highway and see if the problem persists, It doesn't cost much. What was wrong with the fuel pump to cause flooding, that is a strange fault in itself as the fuel rail normaly has a pressure regulator that returns excess fuel back to the tank, but without the facts it hard to comment on that. If you have techstream you can probably read the injection duration to find out if the engine is being told to run richer than normal when hot.