4200 Primary/Secondary Cat Replacements

[Kyle4200]

Sounds like exactly what I had.

I've got a H pipe on mine, it is LOUD!!!!
X pipe may be the more socially acceptable option.

Did you have the same codes or the same symptoms? That's my question now H or X, just waiting for Benny to get back to me then I can order, I've watched the videos of yours and it sounds very nice!! We'll see what happens...

 

[jayblue]

Just been for an MOT and failed on emissions - the cats in the downpipes are still in place but i have removed the secondary cats (US spec manifolds fitted to my GS) I was a little surprised at this since i believe the primary cats are 400 cell. If these cats are in good condition shouldn't my car have passed no problem?

If it is the case that the primary cats are not up to scratch any more can anyone confirm to that their car passed a standard UK mot test with just one pair of 200 cell sports cats fitted?

 

[2b1ask1]

Did it have a darn good thrash on the way to the MOT? it can make all the difference especially if they have been laid up for a while.

 

[jayblue]

Did it have a darn good thrash on the way to the MOT? it can make all the difference especially if they have been laid up for a while.

Yes it was a good thirty minute run to the garage and i was able to open her up and get everything "up to temp..."

It passed the idle test (just) but couldn't pass the fast idle.

 

[maverick]

Just been for an MOT and failed on emissions - the cats in the downpipes are still in place but i have removed the secondary cats (US spec manifolds fitted to my GS) I was a little surprised at this since i believe the primary cats are 400 cell. If these cats are in good condition shouldn't my car have passed no problem?

If it is the case that the primary cats are not up to scratch any more can anyone confirm to that their car passed a standard UK mot test with just one pair of 200 cell sports cats fitted?

I have magnaflow 200 cell sport cats and my car passed last month with no problems

 

[jayblue]

I have magnaflow 200 cell sport cats and my car passed last month with no problems

Thanks i thought as much. I know Outrun passed his MOT with only 200 cells fitted to his GS too. So something somewhere is not right with my primary cats or mixture control?

 

[rockits]

Mine has US spec manifolds with the primary 400 cell CATs with secondary De-CAT. It passed the last 2 MOT's with no issues at all. On looking at the emissions report there are barely any emissions at all and way under limits which was weird.

 

[FelixV]

I have just ordered the Larini 4 bolt sports cats for the GranSport, primarily to let the engine breathe better and stay clear of the risk of the cats breaking up.

My full setup will include:
Euro 4 bolt manifolds
Larini sports cats
Larini X pipe
Tubi mufflers (no valves)

Also have a BMC air filter, iridium spark plugs and FD brake discs, lines, pads and fluid to install.

Expecting a lot of noise with this setup...

Will report after installation which will probably be in the next 4-6 weeks.

 

[BL330]

Way to go Felix!
You are going to love it.
Does the wife know how much that lot cost and will cost to fit ???

 

[FelixV]

Bruce the car already has the manifolds, X pipes and Tubis so just completing the system w the cats.
And yes the wife does know!

Might also look into getting the car remapped as well or the FD drive by wire module.

 

[2b1ask1]

Might also look into getting the car remapped as well or the FD drive by wire module.

Hi Felix,

Happy to sell you my FD unit £600 and will post directly or via FD for a check and/or re-program if you like

 

[jayblue]

Just to update on this i had to refit my secondary cats to pass the mot. The garage inspected the primary cats during the process and they are in tact and functional - seems weird that there are people on here passing with just a pair of sports cats in place yet my car won't pass with the original primary cats and needs both pairs to do it. At least i have another year to figure out a solution to this one now!

 

[CatmanV2]

Just to update on this i had to refit my secondary cats to pass the mot. The garage inspected the primary cats during the process and they are in tact and functional - seems weird that there are people on here passing with just a pair of sports cats in place yet my car won't pass with the original primary cats and needs both pairs to do it. At least i have another year to figure out a solution to this one now!

What emissions is it failing on?

C

 

[Contigo]

Find a friendly MOT tester, job done I'd have thought. Or sort out your fuel trims.

 

[conaero]

Never had an issue with any of them, and my current one has very little restriction left.

 

[jayblue]

What emissions is it failing on?

C

Just passes idle but failed on fast idle.

 

[CatmanV2]

Just passes idle but failed on fast idle.

Sorry, I meant HC, CO or NOx, or a combination?

C

 

[jayblue]

Sorry, I meant HC, CO or NOx, or a combination?

C

It passed HC and lambda. Certificate says it failed on carbon monoxide content on fast idle.

 

[CatmanV2]

It passed HC and lambda. Certificate says it failed on carbon monoxide content on fast idle.

Without reading back what's been already posted, that's nothing to do with cats but it's overfuelling causing fast idle.

At a *guess* stuck injector of screwed MAF

C

 

[jayblue]

Without reading back what's been already posted, that's nothing to do with cats but it's overfuelling causing fast idle.

At a *guess* stuck injector of screwed MAF

C

That's very useful info thanks. Certainly gives me some other potential issues to examine.