exhaust problems...(smoky and smelly)

[gglantgirly00]

So my car has been smoking a lot lately (mostly when accelerating) and smells strongly of gas (really rich) but the last time I parked it, there was a hint of a burning smell. When it idles, there isn't much coming out of the exhaust pipe, but when I take off, I look in my rear view and the smoke pretty much engulfs the vehicle behind me. Doesn't seem to smoke the whole time im driving but not too sure, mostly focusing on what's in front of me.
The smoke itself seems to be whitish, grayish... but it looks like any other car when they are warming up, except mine is in higher volume and lasts longer (my assumptions). I don't think it's antifreeze/coolant bc the smell isn't sweet at all. It gives me a headache and makes me want to throw up. When I back up, the smell enters the cabin (windows up). My oil looks fine, levels are stable, all fluids look good. The car runs well, even though it needs a tranny mount. It is eating up gas like CRAZY!! My last trip I drove 6 miles and it took a quarter tank of gas. No gas leak anywhere.

Other factors- engine ticks, exhaust leak near engine, might need new head gasket.

I have big plans for this car, but I can't figure out whats wrong with it. I'm almost to the point of trading it in for a 3000gt even though i love everything about this car.

[keith6110]

Sounds like the catalytic converter is plugged up. Definitely something plugged up in your exhaust system.

When on the throttle, is the smoke still white/grey? Do you have to add oil every once in awhile? I recommend changing your oil if you haven't done that in the last 2500-3000 miles. Get the head gasket replaced as soon as you can if you know thats a problem. You will get way better gas mileage when you get that fixed.

Anyway, welcome to TGC!

[AktionCat]

Could always try and throw seafoam into the vacuum lines. I read somewhere once that if you cat does happen to clog up..Either hit it or smash on the gas and that should loosen up some of the crap.

[gglantgirly00]

Could my fuel injectors be part of the problem? im going to replace the head gasket, cat. converter, plug wires, and most likely the injectors and see if the problem clears up. If not, then I don't know what else could be causing it. No codes are coming up on the car. Also, would it help if I switch to a higher grade of gas? Or should I just stick with the basic unleaded?

[4g63lover]

Ok, you need to get a scanner on that thing and look at the fuel trims.

Any codes showing? If the car is dumping gas, it's killing the cat. This would be the reason why you would smell gas out the tailpipe. Though the exhaust leak could also be the source of the smell. As far as the smoke out of the exhaust, I would check the oil. The head gasket could leak in places where it wont overheat or smell but will still mix with the oil. Make sure it is NOT milky or diluted at all.

Check the plugs, if it's for sure dumping fuel they will be fuel fouled for sure.

[4g63lover]

Could always try and throw seafoam into the vacuum lines. I read somewhere once that if you cat does happen to clog up..Either hit it or smash on the gas and that should loosen up some of the crap.

The thing is, if the cat is getting clogged, there is a reason that it clogged. The exhaust is pretty much a closed system so the cat should never clogged granted the car is running right.

The main killer for the cat will be RAW fuel. If the fuel trims are off and the car is running lean you will see a lot more Hydrocarbons (raw fuel) out of the tailpipe when hooked up to a gas analyzer. Now you are probably thinking, if it's is spitting out gas at the tailpipe shouldn't it be rich?

The answer is no. If you are seeing RAW "unused" fuel out of the tailpipe the car is in fact running lean. What happens is the PCM is seeing that the air/fuel mixture has more air than fuel, so it then adjusts the fuel trim by increasing injector on time dumping more fuel to compensate. If the fuel trim equalizes (the PCM sees that the amount of fuel dumped has brought the car back to stoich [14.7:1]) it will stay at that percentage on Short term trim as well as Long term trim as long as the mixture stays there. This will decrease your fuel mileage. This could throw the "fuel trim malfucntion" code without throwing the "system lean" code. The system lean code will pop up once the trim exceeds +30%. On the flip side "system rich" will pop up once trim exceeds -30%

What I am trying to say is, something is causing the car to drink the gas but not completely burning it. Whether it is a leaky head gasket lowering the compression and letting unmeterd air in or an exhaust leak causing a vacuum leak post the Load sensors it could all lead to poor fuel economy and a poor running engine.

Do a compression test and a Cylinder leak down test if you are not sure about the head gasket. I would also check injector pulse width and make sure none of the injectors are sticking.

[gglantgirly00]

Tried to take the valve cover off and it didn't budge. This thing is seized on there. My step-dad (ASE Master Cert) couldn't even get it off. Is there a hidden bolt or is the gasket causing this?

[mko]

tap it with a mallet, use a screwdriver to pry it out. The gasket is shot anyway

Just be cautious not to crank the valve cover

[werntonb]

So my car exhaust (http://www.allexhaust.com) has been smoking a lot lately (mostly when accelerating) and smells strongly of gas (really rich) but the last time I parked it, there was a hint of a burning smell. When it idles, there isn't much coming out of the exhaust pipe, but when I take off, I look in my rear view and the smoke pretty much engulfs the vehicle behind me. Doesn't seem to smoke the whole time im driving but not too sure, mostly focusing on what's in front of me.
The smoke itself seems to be whitish, grayish... but it looks like any other car when they are warming up, except mine is in higher volume and lasts longer (my assumptions). I don't think it's antifreeze/coolant bc the smell isn't sweet at all. It gives me a headache and makes me want to throw up. When I back up, the smell enters the cabin (windows up). My oil looks fine, levels are stable, all fluids look good. The car runs well, even though it needs a tranny mount. It is eating up gas like CRAZY!! My last trip I drove 6 miles and it took a quarter tank of gas. No gas leak anywhere.

Other factors- engine ticks, exhaust leak near engine, might need new head gasket.

I have big plans for this car, but I can't figure out whats wrong with it. I'm almost to the point of trading it in for a 3000gt even though i love everything about this car.

What are you planning with man? I am very excited to see your plan about it. I will catch an update with this. Very interesting! :rockon:

[gglantgirly00]

I plan on converting it to a twin-turbo, 5-speed manual with showroom body kit. Basically, converting it into a galant vr4. I was planning on just buying a galant vr4, but they are very hard to come by around here and the company I found online won't ship to the US if I haven't had a car shipped overseas before... I am going to gut the interior and update it. I want it to be a show car, but be able to take it to the strip on occasions.

[gglantgirly00]

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