| sarlek |
| I have just bought MDX 2004 (US spec) to be used in a country where only leaded fuel is available. What can I do to protect my catalytic converter? Are there any additives I can add to the fuel? |
|
|
| polyian |
| You want to protect the converter then have it removed and a pipe put in it's place till you return. Or be prepared to replace the converter when you return as it will be toast. Maybe you can sell the MDX in that country before you return. Any leaded fuel will destroy the converter and the vehicle won't pass any emission tests on re-entry. |
|
|
| RN7676 |
Right, the leaded fuel will not hurt anything other than the catalytic converters in the exhaust system. At some point the leaded fuel will clog up the catalytic converters and clog up the exhaust sytem causing drivability issues.
The general recommendation is to remove the catalytic converter. Any country that sells leaded fuel will likely not have any emissions requirements where a catalytic converter would be needed.
The catalytic converter is a muffler looking thing inline in the exhaust system in front of the rear wheels.
The only question is does the MDX have additional catalytic converters in the header pipes? Most late model cars do. I've heard them refferred to as "pre-cats" or "phase 1 cats" or something like that. Most cars have them built into the exhaust manifold or exhaust header pipes and are not easily removeable in most cases. I'd bet the MDX has them (in addition to the regular catalytic converter) but I'm not sure. |
|
|
| sarlek |
| My Thanks to Polyian and RN7676 for responding to may mail. What type of drivability problems should I anticipate if the catalytic converter clogs up? Will it affect the engine's performance? |
|
|
| Icura |
quote:
Originally posted by sarlek
My Thanks to Polyian and RN7676 for responding to may mail. What type of drivability problems should I anticipate if the catalytic converter clogs up? Will it affect the engine's performance?
I am also concerned. Any other opinions? |
|
|
| RN7676 |
Eventually the lead in the fuel will clog up the catalytic converter. The exhaust flow will get restricted and eventually the car just wont run at all. It happened fairly often in the late 70s when leaded fuel was still commonly available in the US and some cars had catalytic converters.
It wont hurt the engine. It will just start running poorly, start getting bad fuel economy, and eventually just not run at all. Once you clear the exhaust restriction they typically come right back to life.
Now I have no idea how long it takes to clog it up. I don't know if it takes 10 tanks of gas or 1000 tanks. And it probably also depends on how much lead is in the fuel ... but eventually it will clog up.
You need what is called a "test pipe" installed in place of the catalytic converter. A test pipe is just a straight through pipe. They are commonly sold for high performance applications. Search ebay, you'll see tons of them. However I doubt you'll find any pre-made ones for an MDX. Any exhaust shop can easily and quickly make and install a test pipe for you and it should probably cost less than $50. Most shops in the US will not do it because it is a Federal emissions violation against their shop if they get caught. So you might have to get it done after your car gets to the country selling leaded fuel. Any exhaust shop in a country selling leaded fuel probably does it all the time on US spec cars.
The car will probably run slightly louder with a test pipe. The catalytic converter is not a muffler but it does have a silencing effect. So removing it usually increases the exhaust noise slighly.
If you get a test pipe, keep your catalytic converter if you have room to store it. They are very expensive and you will need it reinstalled if you bring the car back to the US. |
|
|
| RN7676 |
| catalytic converter |
|
|
| TR1 |
| I'm not too up on MDXs, but you will probably need a rear O2 sensor simulator. Most modern cars will throw the CEL and go into limp mode when the rear O2 sensor realizes you do not have a cat. The sensor tricks the ECU into thinking that the cat is on and functioning. They're like $50 or so for most cars... |
|
|
| RN7676 |
quote:
Originally posted by TR1
you will probably need a rear O2 sensor simulator.
Wow, good post from a 1 post junior member! I can't beleive I forgot about that! Anyone mentioning O2 simulators must be a current or ex performance junky!
..
..
He's right if you put a test pipe in you will definately get a check engine light for O2 sensor out of spec (or some related code).
O2 sensor simulators are readily available for performance cars. I'm not sure if the simulators are vehicle specific or not. .... ie, I know you can easily find one for any late model Mustang, but I'm not sure if it sends the same signals that an MDX is looking for. It probably wont plug right into the wire harness either ... The simulators all do the same thing, so it would be a similar signal, but I'm not sure how specific that signal needs to be for an MDX or any other car.
All that said, you may just be better off leaving the catalytic converter in!
Or better yet, try to figure out why any crazy country is still allowing leaded gas to be run through passenger vehicles and get them on an unleaded standard like the rest of the environmentally responsible countries!
Although it can eventually kill you, lead additives arguably do make for better gasoline!
I mean no dis-respect by "crazy country" :-)
smoke break's over. I'm out! |
|
|
| TR1 |
quote:
Originally posted by RN7676
Wow, good post from a 1 post junior member! I can't beleive I forgot about that! Anyone mentioning O2 simulators must be a current or ex performance junky!
..
..
Thanks RN7676, I'm an anything with a motor junky. I agree removing the cat is a PITA, but have you ever smelled the exhaust from a car with a cat running leaded fuel? I would definintely do the test pipe like RN suggests...
If you are not willing to do it yourself, it should not be more than an hour or 2 of labor at a shop. The trick will be finding one willing to remove the emissions equipment. If you explain your situation (ie moving out of the country) I'm sure there is someone out there that would perform the service. The cost of swapping the cat on and off + a test pipe + an O2 sim should be much less than the cost of a new cat.
Also, if the cat does clog, #1, the car won't run until you change it out anyway and 2: I've heard (but never actually seen) that it can cause engine damage. The heat loads from a clogged cat are supposed to be very high, and I've heard it can cause burnt valves. Valve job on an MDX would be $$, not to mention any other damage all that heat could do to other things. I would not risk it, imo. |
|
|
| TR1 |
I just thought of one more thing... Depending on the level of lead in the fuel, you may toast your O2 sensors as well. There are several companies out there that modify auto engines for use in aircraft. The subaru flat 4 and 6 ( http://www.eggenfellneraircraft.com/ ) and the Mazda Rotary (http://www.rotaryaviation.com/ , http://www.powersportaviation.com/ ) are 2 common conversions.
One thing that is universal between them is if you want to run Avgas, they need a non-O2 sensor based engine controller. Avgas in the US is generally of the 100LL type. This stands for 100 Octane, Low Lead. Now the "Low Lead" moniker is in comparison to old school Avgas, not leaded auto fuel, so I have no idea how the lead levels compare. Needless to say 100LL will toast most O2 sensors.
You need to run front O2 sensors in your car, so there is no simulator or anything you can by to bypass running them. Bottom line, you may be buying a new set of O2s if you run leaded fuel. I would even consider brining a spare set. The Bosch sensors that are available aftermarket for our cars are actually re-packaged NTK sensors. (At least they were when I bought mine) NTK is the OEM manufacturer of the sensors in the MDX, and are the same sensor you get from Acura, at a much lower cost. |
|
|
| TR1 |
Here's something I read on Wikipedia...
Leaded gasoline contaminates the oxygen sensors and catalytic converters. Most oxygen sensors are rated for some service life in the presence of leaded gasoline but sensor life will be shortened to as little as 15,000 miles depending on the lead concentration. Lead-damaged sensors typically have their tips discolored light rusty. |
|
|
|
