Hello I just picked up a used 2015 Lexus RCF with 67k miles. Only mod is the apexi n1x cat back exhaust, and apexi throttle response.

so far I’m in LOVE but a few things I cannot pin point.. noticed a smell coming from the outside of the rcf. Smells smoky? If I have the windows open I can smell it and when I turn it on immediately smell it, sitting idle, and after turning off the car. will stain my clothes with that smell.
I’ve brought back to the shop and they don’t see any oil leaks and mention could be from the after market exhaust because it’s running too rich?

please someone help me or steer me in the right direction

 

Could be an exhaust leak? That is what is sounds like. Maybe, gasket issue with the exhaust.

 

appreciate the quick response. How can I determine which part is leaking? If that makes any sense and if there is a leak what would be the next step?

 

If you think the smell might be from the exhaust, what you can do is when the exhaust is cool, spray some soapy water onto the exhaust joints, start the car then watch the soapy water for bubbles forming. This indicates an exhaust leak. Many times people put a catback exhaust on improperly and could have an exhaust leak without even realizing it.

 

thanks I’ll give that a try. Based off smell can you determine what it is? Like what does a oil leak smell like? Compared to a exhaust leak.

 

An exhaust leak has a distinct sickening effect to it usually. Sometimes it might smell sweet in the case of performance cars such as the RC F, or if the leak is in front of the cat. An oil leak itself has no smell but when it burns off it smells like... I guess you could say it has a tangy but musty smell, its hard to put into words. Usual spots to look for an oil leak would either be your valve covers or your oil pan gasket (the latter one rarely gets hot enough for the oil to actually burn off so, thats unlikely)

 

If they changed the oil before you bought it, they might have spilled a little around the engine....but you'd need to warm up the car to smell it. Or if they 'cleaned' the engine and used any cleaning or shine sprays, those may need to cook off a bit.

 

^^^^^This!

 

Yri's advice reminds me this link which I watched few days ago.

 

I asked when the last oil change was and they dont know.. lol highly doubt they cleaned the engine. They kept pointing out the after market exhaust because it’s running rich? So does that mean having a cat back exhaust has a smell to it?

 

Believe it or not....

I have smelled that on quite a few Toyota products, to me it was like the smell from an old camp fire but faint.
This was back in the 90's working at a Toyota dealer and sometimes it was when doing pdi's, pretty sure it was exhaust related.
What you're smelling could be something else.

 

No it does not. I don't have an Apexi, but none of the aftermarket exhaust SHOULD have a smell once they have properly broken in (for the first 50 - 100 miles, there is). Only if there is an exhaust leak, can there be smell.

 

Morning all thank you for your inputs! The rcf ended up hitting a check engine light so I bought a obd2 scanner and a code popped up. “P0136 - 02 sensor circuit bank 1 sensor 2”

im assuming this is the 02 sensor attached to the exhaust? Or mid pipe? How much do these cost from Lexus or can I purchase a after market one from a local auto shop?

I hope to god this will fix the smell

 

Yes, that is what I suspected above. It is an exhaust leak. Your Apexi is leaking.

 

It's not the 02 sensor, its a gasket leak up front where the exhaust connects to the headers. Just need to tighten the bolts or replace the gaskets.