A little history.
When I bought my 87 240 last year it had a bad AMM. It was running poorly and very rich. I immediately replaced AMM, plugs, rotor, cap, wires, cleaned throttle body and idle valve, injectors, etc.

I passed smog but didn't get the report.

Car idles fine but when I'm driving at a steady speed I occasionally hear a surging, whooshing sound which doesn't seem to effect rpm's. When I step on gas it's occasionally sluggish in reacting, other times fine. No sluggishness I notice when cold.

I hit the cat. converter with a rubber hammer and shook but didn't hear any rattling. Don't know if it's my imagination but seemed to have more response for a day or so.

Posted a couple weeks ago and one response said flow from tailpipe would be steady if bad, flow seems pretty steady.

Am I correct in suspecting cat. converter?

thanks in advance

Kirk S.

I do not think that a BAD (clogged) CAT would produce a steady flow.As you know the CAT is made of ceramic. Broken up would clog the system. Do you have the original CAT? good luck..
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john,,1985, 245:GLTi 241k mi..so.california

The cat. converter was not original. I just went ahead and had it replaced yesterday. Didn't know how long the previous owner drove around with the bad AMM hence the very rich mixture.

Seems like the timing had been retarded a bit too, probably to try and make up for the rich mixture. Anyway, I advanced the timing a little bit and with the new cat. it seems like I have a bit more pep. No timing light as yet but will purchase soon to get timing perfect, it's not pinging though so I'm o.k. for now. Probably wouldn't hurt to clean the injectors now too.

thanks for the response

Kirk S.

p.s. Think I met you at u-pick parts last year around this time.