Replacing Pre-cats

ChrisHumes · October 5, 2005, 07:34

Could someone answer the following please and tell me what part these replace. I assume that the TRD replaces jsut the Pre-cats and the other the whole lot (is precats and main cat??

PPE Header + Hi Flo cat?

and

TRD Exhaust Manifold?

Thanks

Tem · October 5, 2005, 08:14

The precats are in the stock manifold. TRD manifold replaces just those.

PPE header also replaces the manifold, getting rid of the precats. If you take their high-flow cat as well, you will obviously replace the main cat with it.

(header=manifold)

ChrisHumes · October 5, 2005, 12:35

thanks for the reply. so if you replace the cat etc, will the car pass the mot? i guess not?

Anonymous · October 10, 2005, 12:09

If you are replacing the main cat (as opposed to removing it), you shouldn't have a problem with MOT. The pre-cats exist for the American market to accommodate the stricter emission regulations.

In the UK, you should be fine with just a main cat. I am sure someone without the pre-cats can confirm this.

Anonymous · October 10, 2005, 12:13

sorry to jump on post, so rather than removing the pre-cats from stock manifol would it be easier to replace manifold?

jonytom · October 10, 2005, 12:38

Not much easier and a lot more expensive.

Anonymous · October 10, 2005, 13:13

does anyone know where i can get a disscounted mainfold (or a site that sells them?), becuause i want to get rid of the pre-cats, but want another alternative than cutting the existing ones out. thanx

spit · October 10, 2005, 15:21

Occasional checks in the forum's "Buying & Selling" section and EBay are always worth a look.

I have a couple of stock manifolds up for grabs (one with, one without). Not quite ready to post them up just yet - give me a few weeks.....

Tem · October 10, 2005, 15:36

Quote from: "Emmanuel"The pre-cats exist for the American market to accommodate the stricter emission regulations.

In the UK, you should be fine with just a main cat. I am sure someone without the pre-cats can confirm this.

The precats aren't just a US thing, they do affect euro emissions as well. If you take the full Euro 3 emission test, the precats have their place. Euro 3 test starts with a cold car and it measures all emissions from start, through simulated drive, till stop. The precats warm up very quickly and start working earlier than the main cat, making it a lot easier to pass this kind of test.

The sniffer that measures percentages at idle and +2000rpm on neutral can be passed even without the main cat s8)

s8) You won't see any difference without the precats.

Anonymous · October 10, 2005, 21:47

Is that the new, stricter emissions test? If it is, I thought the MR2 and Celica are being axed because they don't pass it anyway... s:? :? s:?