2007 tl. recently replaced o2 sensor due to code but still having exhaust issues.
Usually only notice the smell when I have my windows done or recirc off. Thinking I have a leak somewhere.
Was watching videos of identifying a leak with a leaf blower/shop vac placed in the tail pipe and using soapy water everywhere to check for leak.
Was wondering if I could do this just by running engine and using soapy bubble when engine is cool.

Also smell is somewhat sweet though not sure if its coolant type sweet but maybe just how a 15 year old car exhaust smells. Car definitely smells worse when not using ultra gas

any thoughts welcome

 

By putting the shop-vac/leaf blower in the tail pipe (and sealing it tightly) is closing the exhaust system between the engine and tail pipe to a closed system. This almost pressurizes the exhaust to force the air out of wherever it's leaking from (gasket, flange, etc)
Simply running the engine will not replicate this because without blocking or plugging the tail pipes, the exhaust is still an open system and the exhaust will take the path of least resistance (aka out the tail pipes)

But if the leak is bad enough that you smell it inside the cabin, you probably don't even need to do the shop-vac/leaf blower trick. Simply get under the car while it's warming up and feel around every flanged connection and it should be pretty apparent where it's leaking from.

 

If you're smelling it, you should also hear it. Do you hear your exhaust making a leaking noise?

 

checked under carriage to feel/hear leak. Couldnt find anything or hear anything strange. may try shop vac next

 

If it's not underneath the car, then it must be in the engine bay.
Either the gasket between the primary cat and heads (x2, front or back), or between the primary cat and J-pipe (x2, front or back)

Hopefully it's on the front(s), as they are much easier to access than the rear(s).

 

You sure it's exhaust and not oil / coolant leaking and evaporating / burning on hot elements? If you can't hear it I doubt there is enough (if any) exhaust leak to get sucked back into the cabin.

 

Remember, he who smelt it dealt it!
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definitely faint smell of exhaust in engine bay. seemed to be strongest in front then back though tough to tell as I was getting woozy lol. any suggestions on locating exact spot better than shop vac and soapy water?

 

happens when everything is cool so cant be burning leaks.

 

but dont forget he who made the rhyme did the crime

 

Anyone consider the EGR valve?
.

 

did the leaf blower test and pretty much narrowed it down to the rear primary cat by process of elimination. Not feeling the urge for major repair so will probably leave alone. It tends to go away after the car reaches temperature.

 

Are any of the other O2 sensors original? At this age, it pays to change all 4 of them. Stick with NTK or Denso.
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I would if I was planning on keeping it for long. MPG isnt the greatest

 

I did see lots of dried oil around coils and cat gasket. Wondering if this is something related to exhaust smell or normal for 2007. Smell is definitely exhaust smell that goes away after reaching temp. Spraying soapy water of spot with blower in exhaust doesnt produce any noticeable bubbles.

 

Replace valve cover gaskets. That's probably what you're smelling.

 

I think you maybe right. What are your thoughts on Blue Devil Oil Stop. Im trying to avoid a major repair on the car and have been reading some good reviews on it. Some not so good either though