bigbadspoon

I have a 99 civic with the stock d16 in it. It's been running a little rich since I bought the car but I wasn't too concerned about it until the other day when the CEL came on with a code 45 and it started to smell like unburnt fuel at idle and after shutting down.

I've been running through as many things to check as I can think of, but this seems like one of those problems where you're better off using a collective group of people to solve it.

So, the list is as follows:
-did a tune up 10k miles ago (plugs, wires, cap, rotor, fuel filter, pcv)
-checked coolant temp sensor (280 ohms at ~200 degrees, 1.1k ohms at ~100 degrees). Those numbers seem to be in spec
-check map sensor (~3V KOEO, ~0.6V-0.7V at idle)
-check for obvious vacuum leaks, found none
-put my hand over intake to see if the car still ran (it does )
-check O2 voltage (I only have a multimeter, not a scope, so not much to be learned here, but appears to cycle from about 0.2V-0.9V)

So, a vacuum leak seems a possibility, since the engine didn't stall when I put my hand over the intake, but I'm completely at a loss on how to detect it. I can't hear any hissing, partly because I have a short ram intake, which is kind of loud, and because i have a sawed-off exhaust, which is pretty loud. I tried using a stethoscope on my hoses to see if I could hear any flow, but they were all silent aside from a very slight resonance to the engine noise.

Thinking of going to Publix and buying some dry ice and popping it into the intake manifold and seeing if any smoke comes out anywhere.

Anyway, I'm sure I've overlooked something here. I was only a mechanic for a couple years and diagnosis was never my strongest suit, so any input would be greatly appreciated. If I don't respond to the forum right away, it's because I'm at my parents' for the break and they keep me kind of busy, but I'll be checking at least once a day . Thank you everyone.

BMacls

sounds like my problem. i hope someone has a answer..