Decat and EGR bypass advice please.

[Spanky]

Originally Posted by chrissyboy

no need to look anywhere .yes damage will result to the engine , fact .

If they're stuck open yes, stuck shut - No.

[Jakg]

Originally Posted by chrissyboy

what exactly does the egr do?

Recirculates exhaust gasses (which are going to be hot) into the engine to burn off certain particulates (NOx mainly)

Originally Posted by chrissyboy

no need to look anywhere .yes damage will result to the engine , fact .

You can't state "fact" with no evidence.

Still waiting to find out how a decat damages the engine...

[soapy]

Many diesel owners on here have attested to the fact that the egr bypass along with the air intake mod allows the m47 engine to breath easier and therefore be more efficient performance and economy wise,fact.

[chrissyboy]

Originally Posted by Jakg

Recirculates exhaust gasses (which are going to be hot) into the engine to burn off certain particulates (NOx mainly)You can't state "fact" with no evidence.

Still waiting to find out how a decat damages the engine...

not cat i said the bypass would damage the engine .

[ardvark]

This discussion needs to be sorted by people who KNOW and not by people who think they know. Two questions needs to answered:-

1) Will a EGR bypass lesson the life of our engines long term?

2) What are legalities of decatting our CDTi engines and again will it lesson the life of our engines long term?

I, along with other members have both "mods" on our to do list and we need to know once and for all.

[chrissyboy]

Originally Posted by Jakg

Recirculates exhaust gasses (which are going to be hot) into the engine to burn off certain particulates (NOx mainly)You can't state "fact" with no evidence.

Still waiting to find out how a decat damages the engine...

yes ,but then what happens ?

[Jakg]

Originally Posted by chrissyboy

not cat i said the bypass would damage the engine .

Originally Posted by chrissyboy

...the cat is also there for a reason ........ without the cat your creating piosonous gases ...without it will create pressure that will end up breaking the cat and back pressure ..

Originally Posted by chrissyboy

yes ,but then what happens ?

Errrr, what?

The EGR recirculates (some, well very little) of the exhaust gas back into the engine, replacing some of the air. The engine is then burning an air / exhaust mix, burning up some of the "waste" remnants in the process. This reduces exhaust emissions (and potentially may slightly improve MPG). It's a cyclic process.

Remove the EGR, and your burning "straight" air, like 99% of the pre-2000 diesels / petrols. Even if it the engine was now burning hotter (which I doubt) the CDTi is already massively overcooled anyway.

[Jakg]

Originally Posted by ardvark

Will a EGR bypass lesson the life of our engines long term?

No

2) What are legalities of decatting our CDTi engines and again will it lesson the life of our engines long term?

Will it lesson the life? No. Although it due to extra power you may work the engine harder, which might shorten their life - but thats not a direct consequence

Is it legal? Yes & no. It's illegal for a new car to come without a cat (construction & use) - but your cars already been type approved. Your car only has to pass an annual inspection (MOT), which it will easily pass without a cat (visual smoke test - decat will probably make it smoke a bit more but mine still passed with ease)

It *may* be illegal to modify an exhaust to make it create more pollution (it is to make it noisier), but it's not illegal to replace a part with something else which also makes it noisier (i.e. cutting out the cat vs getting a stainless steel system without a cat at all). This is one of the EU laws, that comes from Germany where they have a strict TUV-approved mods list for what you can & can't do, and to avoid you modifying parts to get around it. The UK does not have such a policy, and I've never heard of the police in the UK using this law

The worst the police / VOSA could do (as in by the way of roadside testing to determine if something is "correct" if they want to be anal) is subject you to a roadside MOT, which the car would pass easily.

I would have no problems running without a cat, and have done for the last few months (probably nearing 6 now)

............

[chrissyboy]

Originally Posted by Jakg

Errrr, what?

The EGR recirculates (some, well very little) of the exhaust gas back into the engine, replacing some of the air. The engine is then burning an air / exhaust mix, burning up some of the "waste" remnants in the process. This reduces exhaust emissions (and potentially may slightly improve MPG). It's a cyclic process.

Remove the EGR, and your burning "straight" air, like 99% of the pre-2000 diesels / petrols. Even if it the engine was now burning hotter (which I doubt) the CDTi is already massively overcooled anyway.

not replacing but adding too the air .combustion can happen at the wrong time ie on the up stuck forcing the piston down and can score the bores. isee someone has done a post already that explains exactly why you shouldnt by pass the egr ... another problem that is caused by the bypass is poor starting .hands up all the guys that have done the by pass that have poor starting issues .... wow i didnt realise there was so many .. the egr will work every 30 seconds when travelling at speed ,helping to cool the high temps the cylinders reach. it is nt as you say a very little it is around 10 to 12% it can also damage the cat ,i guess that is why the cars with th by pass have the cat removed .. the by pass will also lead to over heating isues too

[andy willi]

chrissyboy please tel me why you think the cylinders will get hotter and why would the engine be at risk of damage i will be intrested in your thourts about this please

andy