28 replies to this topic

[850T5M]

Hi, I recently did a complete stage 0 on my car but I've been smelling really bad exhaust smells when the car is pushed hard at 10-11psi...It smells like burning or gas or something...not sure. Theres no smoke coming out of the exhaust, just smells really bad. The smell goes in the cabin if a window is opened. Is it possible that the O2 sensor is not properly sensing the A/F ratio and causing a lean/rich mixture?

How would I know if this is the problem, do I do the blowtorch/volt-meter test on the sensor? I think theres 4 wires on the front o2 sensor, which one do I have to plug, one of the whites as the positive right and use the shell as a ground? (if not, then the white wire i'd guess)

Another question is, would a faulty O2 sensor give me bad gas mileage and/or less performance? Im getting around 14-15 MPG in highway/city driving mixture. I have -22 vacuum so its not a vacuum leak. I havent owned the car long, so I dont know when the O2 sensor was changed (if it was ever changed) and i dont know the proper MPG i should be getting...i think a little more than 14-15 tho.

Car has 210000km, or 130k Miles

Thanks!

[Gilhuly]

Check engine light?

O2 sensor will definitely affect mileage and your's is very poor. I'm chipped and getting 24-25. you should be getting a minimum of 20-21.

[whoa]

Gilhuly, on 22 March 2010 - 04:48 PM, said:

Check engine light?

O2 sensor will definitely affect mileage and your's is very poor. I'm chipped and getting 24-25. you should be getting a minimum of 20-21.

That's quite a savings: about $266/year (if gas is $3.50/gallon, you drive 10K miles/year, and you improve from 21 to 25mpg). Are there some chips optimized for mileage rather than HP?

[Falcone]

OP, on a cruise with even throttle imput around 60km/h you should be easily able to obtail less than 10l/100km. I just replaced my o2 because when it was stolen, some as$ cut the sending wire, and my fixes kept screwing up. I was lucky to see under 50L/100km, but it was totally toast.

I replaced mine (boshe) with a NGK one I got from fisher auto for $186 taxes in. Usually you'll trip a code like a "heated oxygen sensor signal faulty or missing" if its screwed.

Hows your plugs/wires and fuel filter? Those will also screw your mileage up.

[Fudge_Brownie]

whoa, on 22 March 2010 - 05:04 PM, said:

That's quite a savings: about $266/year (if gas is $3.50/gallon, you drive 10K miles/year, and you improve from 21 to 25mpg). Are there some chips optimized for mileage rather than HP?

Yep. You chip your right foot to go easy on the gas pedal. Normal driving with a factory boost controller and you'll rarely ever see boost. Therefore, who cares what chip you're running. Please, do not debate gas mileages here. No one will accurately depict the current condition of the car, driving style, driving conditions, ambient temperature, altitude from sea level etc. For example, if he is doing all cold start city driving, 14-15 might be quite good. Start another thread, perhaps under Performance, to address your question if what I just said doesn't handle it.

OP, as someone already asked, check engine light on? If so, get codes and report back.

A faulty front O2 sensor will typically cause the car to run rich and therefore negatively effect gas mileage. If you do choose to replace, search the forum to read people's advice about replacing with generic models. Most recommend avoiding them.

If we want to assume your O2 is original, at 130k, it might not be a bad idea to replace it regardless.

A boost leak will leak metered air causing you to enter a rich condition under boost. If you aren't confident of your intercooler hoses, you can build a boost leak tester (google for more info) from basic parts to isolate a leak. Heads up, there's a factory installed pin hole in the bottom of your intercooler to drip execcess oil build up. Plug it for easier isolation of other leaking air.

[850T5M]

Thanks for the replies guys. The CEL is not on in the car, and I live in montreal where it has been really cold for the past few months therefore every start up is a cold start which i know will bring down my gas mileage. The plugs/wires were changed last week with OEM. The fuel filter still hasnt been installed tho. As for the boost hoses, i have not checked them...I will have to do a boost hose test if i find out how to do it...gonna google it right now actually.

Any advice which brand O2 sensor to get if my sensor is in fact not functioning?

[Falcone]

NGK or Bosche, but don't do a universal o2 sensor.

[bigmay850]

check your DTC for codes sometimes it stores them w/out a cel

[850T5M]

Ya i checked my OBD1 and theres no codes...last code I got was when i forgot to plug my boost solenoid (since i have a mbc), now i connected it back without any hoses and i dont have any codes...gonna have to check for boost leaks this weekend. I think i might have a small hole in my muffler, idk if its before or after my cat...could that be whats causing the smell? its around the front door area

Edit: Sorry, the hole isnt in the muffler itself, its in the exhaust line I meant...around the area of the front doors.

[ozzimark]

850T5M, on 22 March 2010 - 11:27 PM, said:

Ya i checked my OBD1 and theres no codes...last code I got was when i forgot to plug my boost solenoid (since i have a mbc), now i connected it back without any hoses and i dont have any codes...gonna have to check for boost leaks this weekend. I think i might have a small hole in my muffler, idk if its before or after my cat...could that be whats causing the smell? its around the front door area

Edit: Sorry, the hole isnt in the muffler itself, its in the exhaust line I meant...around the area of the front doors.

If you are moving when you smell the exhaust, you definitely have an exhaust leak, possibly before the muffler. Check for leaks around the exhaust manifold, turbo and downpipe.

[project_850]

http://www.rockauto.com

Not sure if I'm allowed to put that up, but I bought an upstream Bosch 02 sensor for $120.

[Scootdiggity]

850T5M, on 22 March 2010 - 11:27 PM, said:

Ya i checked my OBD1 and theres no codes...last code I got was when i forgot to plug my boost solenoid (since i have a mbc), now i connected it back without any hoses and i dont have any codes...gonna have to check for boost leaks this weekend. I think i might have a small hole in my muffler, idk if its before or after my cat...could that be whats causing the smell? its around the front door area

Edit: Sorry, the hole isnt in the muffler itself, its in the exhaust line I meant...around the area of the front doors.

I would def. check the condition of the charcoal canister hoses, especially the rubber elbows their is one that goes under the pass. side door that is connected by a piece of rubber, the rubber usually goes bad or the hose usually comes out. I had the same smell and poor gas mileage when i had cracks in rubber both at canister and under passenger door, and check engine light never came on even with cracks in rubber I was amazed the light never came on.

[850T5M]

Scootdiggity, on 22 March 2010 - 11:59 PM, said:

I would def. check the condition of the charcoal canister hoses, especially the rubber elbows their is one that goes under the pass. side door that is connected by a piece of rubber, the rubber usually goes bad or the hose usually comes out. I had the same smell and poor gas mileage when i had cracks in rubber both at canister and under passenger door, and check engine light never came on even with cracks in rubber I was amazed the light never came on.

Where is the "charcoal" canister, and what is its purpose? Where do the hoses go?

For the boost leak test, I have to connect a rubber hose to the turbo inlet...what size is it? Basically what size is our intercooler plumbing?
As for the exhaust leak, im gonna have to try to repair that little hole...how would I see if the turbo or downpipe is leaking exhaust?

[Scootdiggity]

850T5M, on 23 March 2010 - 12:20 AM, said:

Where is the "charcoal" canister, and what is its purpose? Where do the hoses go?

For the boost leak test, I have to connect a rubber hose to the turbo inlet...what size is it? Basically what size is our intercooler plumbing?
As for the exhaust leak, im gonna have to try to repair that little hole...how would I see if the turbo or downpipe is leaking exhaust?

its located in front of the driverside wheel well, if your car is equipped, and runs the length of car and other end runs along radiator shroud

[Fudge_Brownie]

project_850, on 22 March 2010 - 11:49 PM, said:

http://www.rockauto.com

Not sure if I'm allowed to put that up, but I bought an upstream Bosch 02 sensor for $120.

You are, and we appreciate links to quality parts sources.

OP, exhaust leak? If it is before the front o2 sensor, so before the cat, then this could cause your car to have unusual AFR's for sure.

Best way is to climb under there and take a look around. Look for rust. If you can reach, you can also wave your hand around and feel for moving air. Obviously, don't forget the exhaust gets hot. One trick might be to "seafoam" the car. Youtube or google, or search VS for more info. It will produce heavy smoke in the exhaust temporarily.

[850T5M]

and what does this charcoal cansiter do?

my mechanic told me that the smell could actually be my clutch. he said it might be slipping just slightly and if its a cheap clutch its gonna smell...I know my throwout bearing is going, maybe my clutch is as well...car needs lots money money i dont have lol. Im gonna start with the basics as i stated, and im gonna look into the charcoal canister. See where that gets me for now.

I was thinking of seafoaming the engine, do you think its bad to do on a 210000km engine? Wouldn't it get rid of carbon build up that is basically giving the car its compression, by removing it would it reduce the compression?

Also, my mechanic has a smoke machine...im gonna ask him if its possible to connect it to my turbo to find the boost leaks/vacuum leaks...and possibly to the exhaust to find some exhaust leaks. As for the O2 sensor, where is it exactly, on the downpipe? My exhaust hole is much after the downpipe...its at the back of the front doors...like the door handle area i would say.

[ozzimark]

Slipping clutch is a relatively easy determination, but has a really unique smell that you can't miss, that is somewhat akin to hot brakes. When you floor it in a higher gear, and then let off it, does the engine rpm stay relatively constant and decrease with vehicle speed, or drop suddenly?

Evap can is for catching evaporated gasoline from the tank. During normal operation, there is a purge valve that opens that allows the engine to draw out those gas vapors.

[850T5M]

2 days ago when I asked the original question, I was "testing" my car with my dad. He was in a car beside me, he says it smelled kinda like brakes, I dont find it did...but thats what he said. I havent tried getting the car up to a really high rpm and just letting go of the gas and checking the rpm...but i know anything below like 3500 will make the car just slowly slowly brings down the rpm...One thing about the clutch/tranny that i noticed is that its relatively hard to shift. Not when driving at normal speeds, but when pushing the car, its really hard to get from first to second, the rest arent so bad...if i wanna downshift, a similar thing happens from lets say 4 to 3, its really hard to get the car into 3rd gear. I know my throwout bearing is making noise, its been making noise since i bought the car...could this problem be a clutch related problem

How long does it take to change the clutch on these cars?

[johnmcm]

My 2 cents as far as where to get an 02 sensor. I just bought one off E-Bay from a seller named sparksnaaben, here is the model # Bosch 15738 Universal oxygen sensor,0 258 986 505 / 503. It is the universal type and was brand new with a price of $42 plus $5 shipping. I was very happy with it and would recommend taking a look.

[850T5M]

johnmcm, on 24 March 2010 - 12:25 AM, said:

My 2 cents as far as where to get an 02 sensor. I just bought one off E-Bay from a seller named sparksnaaben, here is the model # Bosch 15738 Universal oxygen sensor,0 258 986 505 / 503. It is the universal type and was brand new with a price of $42 plus $5 shipping. I was very happy with it and would recommend taking a look.

Anyone else have experience with the universal O2 sensors form Bosch? Is it authentic Bosch or does it look like some replica form hong-kong?