Hey everyone, I'm trying to help out a friend with a 1989 Prelude Si. She recently failed emissions and took it to her mechanic who said that she has a intake vacuum leak which would cost $1200 to fix (the car is on Nantucket so she's definately getting screwed). I searched around the board here and found a few posts about leaking intake manifold gaskets, but she hasn't said anything about rough idle. Are there common problems in the intake system I should be looking for? Any specific difficulties in replacing the intake gasket? Thanks

 

No help for a NOOb???

 

we are gong to need the gas readings for the emission test and the type of test performed please.

 

Gas readings would help out a lot...then we migfht be able to tell what is going on

 

what ever the prob is 1200 is a rip though. tell that mech. to go f-himself.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fastludeh22 &raquo;</TD></TR><TR><TD CLASS="quote"> tell that mech. to go f-himself.</TD></TR></TABLE>

at the least.. =p

 

Sorry to bring this back from the dead, but I finally got the emmissions info from my friend. It failed the CO test: 31.74 grams (limit is 30.00 - I think she would have passed but her boyfriend was in the car with her). The mechanic said that they would need to replace the intake manifold gasket, throttle body gasket and EGR valve gasket. Any thoughts on that??? Thanks for the help.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TorqueMaster &raquo;</TD></TR><TR><TD CLASS="quote">Sorry to bring this back from the dead, but I finally got the emmissions info from my friend. It failed the CO test: 31.74 grams (limit is 30.00 - I think she would have passed but her boyfriend was in the car with her). The mechanic said that they would need to replace the intake manifold gasket, throttle body gasket and EGR valve gasket. Any thoughts on that??? Thanks for the help.</TD></TR></TABLE>

he wants 1200 bucks to change 3 gaskets?

he may be right (i don't know 3rd gen b's) but gasket changes shouldn't take more than a few hours and materials will cost $50 or so.

 

how old is the cat?

 

I bought the gasket set from Advance Auto Parts for $10, so we can firmly establish that the shop she has been going to has questionable billing guidelines.

The car still has the stock exhaust, so it's at least 17 years old. Would an old cat or blocked cat only fail the CO portion of the test? I've also learned that there is a missing piece to the air cleaner assembly. The way it was described to me it sounds like a piece is missing from the air intake hose, so the intake is essentially bypassing the air filter. Would this allow enough contaminants into the intake to cause an emmissions failure (besides the obvious problem of getting all sorts of crap in the engine)? Thanks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TorqueMaster &raquo;</TD></TR><TR><TD CLASS="quote">I bought the gasket set from Advance Auto Parts for $10, so we can firmly establish that the shop she has been going to has questionable billing guidelines.

The car still has the stock exhaust, so it's at least 17 years old. Would an old cat or blocked cat only fail the CO portion of the test? I've also learned that there is a missing piece to the air cleaner assembly. The way it was described to me it sounds like a piece is missing from the air intake hose, so the intake is essentially bypassing the air filter. Would this allow enough contaminants into the intake to cause an emmissions failure (besides the obvious problem of getting all sorts of crap in the engine)? Thanks.</TD></TR></TABLE>

when the car is sitting in one place (a garage for the emissions test in this case) the air is not going to be contaminated with anything really, if theres a vacuum leak its most likely throwing off the map sensor which is part of how the car calculates how much fuel to use, but since you havent said shes failing with HC, so since only CO is failing that usually indicates the cat is bad, i have a brand new cat and my HC is 2-3 times the max when i last took a smog test, but my CO and NOx are both almost 0, its new cat time would be my guess

 

If the cat was bad, wouldn't the rear O2 sensor throw a CEL (assuming that there is a rear O2 sensor of course - you can tell I'm new to hondas)?

 

High CO indicates too much gas, it is burning hence no HC (unburned fuel), You are going to have to make him prove to you that the O2 sensor is either showing rich or lean, if it show lean at a steady 2000 R.P.M. then you may have an intake leak and the computer is trying to command a richer mixture.

He is also going to have to show you how he found the leaks, with carb cleaner or a smoke machine, have him show you that, it is your right by law.

Let see how good he is or is he just going to throw three gaskets at it and then pay you for your parts and pay his own labor when it doesnt fix it. I think he knows what the real problem is and its not $1200 I am afraid to say.

Too much fuel can come from many places, bad pressure regulator, leaking injector, engine temp sensor out of range, air leak, weak cat. and others.

 

Cats have many test to prove their worth, the post O2 sensor, a pre and post smog test and a inlet and outlet temperature test are a few, drive the car like a madman, get it good and hot, run into the test center and do the test right away, this is legal, dont waste time.