Ok, so i noticed that exhaust gases were getting into the cabin of my car. Not safe plus really annoying. With the understanding that my car consumes oil...long story that I have posted on a few times in the past...I have concluded the catalytic convertors are done and need to be replaced. Car has 142,000 miles. Other tell tale signs: My CEL has come on intermittently over the past year from which I have attributed to a documented P0420 Code (Catalyst System Efficiency Below Threshold). Not too mention, I have noticed a drop in acceleration. Ironically, the mpg's have remained largely (if any) unchanged??? Go figure. Anyway, Now that I am fairly well convinced its the convertors, I could use a little advice.

If I am reading things correctly, it seems there are 4 convertors on the TL's. 2 are immediately after the exhaust manifold and the other 2 are, well, further downstream. I am assumming (hoping) I only need to replace the 2 up near the engine...the other 2 shall remain unless someone has good reason that I should replace those as well. I'm trying not to spend a fortune if I don't need to. Since I am replacing the convertors, it would seem logical to replace the o2 sensors as well. However, they seem to be working fine now (i.e. mpg's are good and no "consistent" CEL) and at $120+ a pop I would rather not spend the cash...I believe there are 4 (2 upstream and 2 downstream), correct?

Should I just buy new stock convertors or are there better after market versions out there that I might want to consider. I don't mind spending a little extra cash if they're better performing.

thanks in advance for responding.

 

There are only 3 catalytic converters. The two primaries are right off the engine block. The 3rd cat is the secondary and is immediately after the J-Pipe.

Only the two primaries have O2 sensors, so if you're throwing a code, it's coming from those. Even if your 3rd cat is bad it won't throw a code.

Each primary cat has 2 O2 sensors, one upstream, one downstream.

Consider looking for replacement primaries at the salvage yard to save some $$$. Don't get 'em at the dealer unless you get the wholesale price. You can buy new OE, at wholesale, here: http://www.acuraautomotiveparts.org/...mcomp=List All


Also consider TL-S cats if you go OE as they are a higher flow (lower cell count) than base.

 

07 TL-S cats will fit my 05?

 

Fair question. Not positive.


But I think there is only one version of PCD's and they fit all trims as far as I know. Indicates to me that primary cats are the same fitment for all trims. Also all '04 - '08 are the same OE part - except the TL-S. But I assume the TL-S is different because of the cell count, not the fitment.

 

Do you know why your car burns oil? If you don't get that fixed, you will destroy the new cats. If it's nothing major, throw an oil with a high HTHS and super low NOACK like Redline 5w-30 in there and see if the oil burning stops.

 

I have my 2 primary cats from my 04 if you want to buy them. They have 120,000 miles on them but were working fine when I removed them to have the turbo kit put on

 

I don't know. Car was fine until ~90K when I noticed the oil light flicker....immediately pulled into a gas station and checked the oil and it was bone dry. Why just a flicker baffles me...it should have reached out and slapped me long before it ever got to bone dry. Why not flicker when its a quart or 2 low, not when its empty?! Anyway, that was a long time ago and I'm sure that did some major damage and now it consumes about a quart (sometimes 2) every 2-3 thousand miles. I've owned a lot of cars in the past 25 years and never had one car ever leak oil or consume it - partly because I've always wrenched my own cars and partly because they have all been Toyotas or Hondas (aka Acura's). I have read a hundred posts all over the internet about Honda's consuming oil so its not uncommon but have yet to read why they are doing it.

Back to your original question - is the problem major? I would call it mostly annoying since I have to watch my oil like a hawk. The oil light is useless as a warning so I drive around with a gallon of oil in the trunk and check it nearly every time I gas up. I agree that as long as the issue continues, I will certainly burn through another set of cats. The gamble is how long I can get away with it. I'm trying to get another 2 years (~50,000 miles) out of the car without spending a fortune to make it happen. Otherwise, I should just dump it now which is not what I wanted to do because I still like the car and I own the pink slip. Short of rebuilding the motor, what else am I to do?

I would defintely try the Redline if it were to solve the problem but I'm guessing it won't - I think the problem is bigger than that and no oil is going to create a better seal at the rings.

 

The problem is, that light is not a low level warning light. That's a low oil pressure light. You have to be completely out of oil for the low pressure light to come on. This is 10x worse than just being a few quarts low on oil. If the oil is getting past the rings and into the combustion chamber, Redline will help. It will give a better ring seal due to the super high HTHS and low evaporation (NOACK). However, it could be expensive burning a $10 a quart oil. At a minimum I would run a 10w-30 of any brand, maybe a 10w-40. Check the PCV system for excessive oil or for being plugged. This can cause your oil consumption.