oxygen sensor

[rich30769]

Recently I changed the oxygen sensor(late August)on my 86 300E , almost immediately noticed when I decelerate I hear back pressure from the cat. I figure the cat. probably has to be replaced(car has 193k mi. on it and also noticed that the metal is peeling). I don't smell rotten eggs or anything. My question is, once I change the cat. (did I wait to long?) do I now have to again replace the oxygen sensor?

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Richie
1986 300E
tint windows
clear corners
euro headlights
16"chrome lorinsers RS90
soon to be 94/95 taillights

[engatwork]

you shouldn't have to
engatwork
'95 E320
'97 Honda CRV

[CMuc]

What do you mean back pressure? Do you mean "back firing" or "popping". If it is doing either of these, you probably have an exhaust leak at the o2.

[rich30769]

quote:

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Originally posted by CMuc:
What do you mean back pressure? Do you mean "back firing" or "popping". If it is doing either of these, you probably have an exhaust leak at the o2.

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What I'm getting is a popping sound.It definitely is NOT backfiring..