As y'all are aware, I bought the 2.5" spun Magnaflow universal cats as part of a custom exhaust system. I dropped the car off to a friend last weekend to do the install and welding, and he will have the car until Sunday.

He called me a few mins ago, while he was underneath the car. He tells me that he is reluctant to mess with the factory cats, because they appear to be part of a larger piece that bolts directly to the manifold.

I told him that this is a rather common swap, as is apparent on these forums. So, to you guys who have done it or have had it done...

-- does this sound familiar? What does he need to do to put these cats on? Also, he is having problems finding the O2 sensors. He is about to see if he can find them from under the hood, instead of from under the car. He says the cats are pretty high in the engine bay. Where are these sensors (or, how high are they?). I am presuming there are 4 total, 2 before and 2 after.

I have never seen the area he is talking about. Any info would be helpful.

Thanks in advance...

 

UPDATE: The guy is good on the cats, but he wants to make sure of the new placement of the O2 sensors (which he has located). Where does he need to place them, ideally, in order to avoid throwing codes?

 

Phil, the upstream O2 sensors plug directly into the cats on the inlet side, then aft of the cats (downstream O2 sensors). The cats don't directly bolt to the manifolds. There is approx. 4' pipe aft. of the manifolds welded to the inlet of cats.

 

Are you saying that the upstream sensors are literally placed in the inlet pipe (the 3 inches or so of pipe before the "business" portion)?

Then, it sounds like the downstream sensors can go wherever, so long as they are downstream. Is this accurate?

 

Phil, my previous post describes the stock cats i.e upstream O2 sensor plugs directly into the inlet end of the cat, whilst the down stream O2 sensor plug in just aft of the cat. For the spun hi-flo cat, the upstream O2 sensor is fitted just prior to the cat (the spun cat doesn't have an O2 sensor fitting) whilst the down stream O2 sensor is plugged in just aft of the cat. Your basically placing the O2 sensors the same as stock except the upstream O2 sensor is not plugged directly into the spun hi-flo cat but just before it. Perform a hard re-set of the ECU, drive her in Normal transmission mode for a few hundred miles then drive her in Sport mode real hard. Let us know how it goes. Though she'll ooze noticeable more power, one thing I know for sure is noticeably crisp and quick throttle response with an authoritive exhaust bark, the likes that will make it difficult for you to leave her alone.

 

Don't put the downstream too far from the cat as O2s need to be HOT.

 

yep, jagv8 makes a very important note to place the O2 sensors as close to the cats as possible.

 

Alright, I went to the spot where my car is, and developed a plan for O2 sensor placement...should be ok.

My next question: Under the stock pipes, between the resonator and cats, there is a black metal bracket of some sort. This, in stock configuration, is found under the small portion of raised pipe (the pipe is raised over this piece).

As far as we could tell, the pipe does not actually touch this bracket at any time. We are guessing that it functions as 1) a way to secure the plastic covers found around that area and 2) a way to ensure the exhaust piping, if broken, will not fall to the ground.

What did y'all do with this piece when your stuff got swapped out?

 

Though I bought my STR with the plastic under engine and transmission cover missing, I kept the black bracket that secures it on.

 

The guy doing this work asked if he can cut this bracket and remove the center portion, thereby still being able to secure the covers while not having it be located under the piping at all. Is this problematic?

 

Shouldn't be a problem as long as he keeps hot pipes an appropriate distance away from plastic cover.

 

..sorry for the late reply bro,but I too am getting my Hi-flow cats installed on Wednesday finally. My question to you is did your friend have to remove the manifold to disconnect the oem cat to fit the HI flow cat or did he just do it from under the jag?(basically is the OEm CAt bolted to a pipe connected to the manifold?) Secondly how do you perform a Hard ECU reset? Can you do it with a OBD2 scanner? If you or anyone else can answer these two questions that would be great.

Let us know the final outcome

 

The OEM cats are welded to a short length of pipe that is bolted to the exhaust manifold. Just unscrew the two nuts holding the pipe to the exhaust manifold then cut it from the OEM cat, then weld it to hi-flow cat. I left you a PM on the hard re-set of ECU.

 

I wanted to clarify what you said earlier about "removing the earth(negative) cable and touching it to the positive battery terminal for 10secs". Now when you say that do I take the disconnected negative cable and touch it to the positive battery terminal while the positive cable is attached to the battery??

**I attached some very useful info about after reseting the ECU, you will get a DTC error code P1000, and you have 7 steps to do for reprogramming, take a look at pages 4-8. Do you think if I do what you mentioned earlier; will it give me the same solution as what I sent you with performing the 7 steps.

Please do let me know and thanks again for your help.

Take care bro.
TAriq.

 

Yes, touch the detached negative cable end to the attached to battery positive terminal. I never heard of anyone recieving error codes following a hard re-set? The cars window, moon roof, and emergency brake modules will re-learn their functions.

 

jag79, ok, I know what you mean by recalibrating the systems outlined in the info you passed on to me. The info serves as a means of monitoring and calibrating. I'm not sure if the processes are involved in clearing adaptive learning (learned behaviors conveyed by the driver to the adaptive learning program)?

 

..lolz.ahhh soo confusing on what to do, alright since you have done the hard reset before, and the process you told me about I will just stick to that for now, lolz....But hey, you have done a hard reset on yours im assuming right with the procedures you passed onto me?

 

Yep, git those hi-flo cats on, x-pipe on, delete stock resonator, dump it all out of flow-through or turbo mufflers (a little quieter), hard re-set of ECU = Vroom!