Hello all, just bought a 2006 Crown Victoria with 138k miles.

Driving it home, the check engine light was on, I assumed it was the EGR valve was bad since it was almost stalling out at stops. Smog showed it was throwing three codes, one for EGR, one for the MAP sensor out of range, and one for an O2 sensor reading too lean. I replaced the MAP and EGR valve, and the CEL came back on. Haven’t had it scanned yet, but just a little back story.

Here’s my question. At a full stop it jerks forward repeatedly as I ease off the gas, other than that it seems to run fine. It doesn’t, however, sound like a crown Victoria should. No abnormal pinging or anything, but it just doesn’t have the deep roar it should. Sounds kind of lame. Hopefully that makes sense lol. Almost sounds as quiet at a v6.

Wondering if that’s a sign the intake manifold may not be sealed or maybe another issue.
Any help is appreciated!