Dear Fellow Brickboarders,

Hope you're well. This is a narrow, technical inquiry.

Can anyone identify the specific difference(s) between (header) exhaust pipes for EGR (Exhaust Gas Recirculation) and non-EGR engines? Ideally, I'd like to hear from those who have actually seen (handled) both types of pipe.

For example, does the EGR-compatible engine pipe have an opening not present in the non-EGR-compatible engine pipe (or vice-versa)? If so, where is the opening that defines which pipe is EGR-compatible and which pipe is not?

Thanks for your help.

Yours faithfully,

Spook

i have handled supposedly both and installed both and have yet to find a difference. (unless you count the minor variation of the bung location important)

imo this is a distinction without a difference

to my knowledge ALL the business part of egr functioning on 940's begin and end on the engine block or just next to it on the sheet metal as attachment points for egr valves

Dear trichard,

Hope you're well. Thank you for confirming what I suspected!

So, is the sealing ring (Volvo #1266118) needed - or not needed - between the engine pipe and the cat converter?

VADIS - the superseded dealer parts/service database - shows that the sealing ring is needed for non-EGR systems. If so, on EGR exhausts, how does the engine pipe fit to the cat converter?

Yours faithfully,

Spook

the egr cars i have worked on all had rust issues around the sealing pipe ends of both the cat and header requiring creativity to solve.

on 93's and later a sealing ring was what i found most often if parts were original because the opening of both cat and header where they join were flared with a spin flange.

a lousy setup imo.

if you are replacing both cat and header then it really does not matter what you buy as long as the meeting ends are the same. flared with spin flange or flat with a welded flange.

if only the header i have only seen flared headers aftermarket for later 940's but maybe welded flange ones are available.

if you can weld and are creative you can make anything work together.

I posted this awhile back and think it is a neat alternative to the clamps that tighten up the header pipe to cat. converter connection (squeezes the flared ends to the sealing ring):
https://www.brickboard.com/RWD/volvo/1625179/940/960/980/V90/S90/neat_cat_converter_header_pipe_connector.html
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Mine:3-940s running, 1-740, 2-940 parts, dtrs:3-940s running