G50: CA Smog Report (benefits of aggressive maintenance)

[3Q Jay]

Here is today's report on silver.

The HC is a bit higher than i'd like, but the car had been sitting cold for a week, i ran it for 5 minutes in the garage, drove 2 miles grandpa-ish, then drove the remaining 2 miles to the smog shop with a few brisk accelerations to 4000-6000. cats prolly didn't get all the way up to temp. car idled for about 10 minutes to do all the pre-amble before going on the rollers.15 months and about 5000 miles ago i did plenum#2 including new NTK O2 sensors, cleaning upper and lower runners to spotless, rootering out the EGR tube, cleaned EGR well, replaced BPT (don't think it was really bad, but.....).

for comparison, here is the previous bi-annual report (July 06). at that time i had done plenum #1, with uncrusting the EGR elbow at upper plenum, and replaced plugs with NGK double iridiums.



lastly, here is the baseline--Feb 2005 prior to purchase.

[goody90q45]

There's a major reduction in NOx emissions between the 3rd and 1st test and even the 2nd and 3rd. Do you think it's new O2 sensors or cleaning the intake path that caused it? Pretty good numbers Jay and at least you know that you're getting the best MPG (and lowest emissions) that the Q was designed for. With $5/gallon gas and a daily commute that's pretty important.

I barely passed smog about 6 months ago , just beating the NO by 1 ppm and the CO was close to the max also. The tech explained it as attributable to a few things but the one that caught my attention was leaky injector o-rings. My 94Q started a little different all winter long and I know I had an o-ring or two leaking and it showed in the smog test results. I have a Deatschwerks fuel rail ready to install which will cure the leak and bring my mpg up to where it should be. I'm getting 13.5-14 mpg where I used to get 15-16 mpg.

We Californians complain about having to be smog tested every 2 years but it's made huge improvements in air quality. Anyone who lived in the L.A. area during the 60's will agree. The smog test forces you to keep your engine running efficiently and probably saves you money in the long run, especially with $5/gallon gas. Too bad it cost $50-$80 to have it done (X 5 cars in my case).

[3Q Jay]

hmmmm, IOM doesn't seem to be getting much attention---i thought you guys would be more interested in this....

Mike, I'm quite convinced the NOx was nixed by the EGR cleanout.

side note: new 01 Jan 2008 enhanced test for 'evap' pinches canister hose with small pressurising of tank to check for vapor leaks.

[maxnix]

LA air in the sixties inspired the whole emission movement in the US.

Mexico city is far worse. Haven't been to Beijing.

[Q45tech]

Everybody knows the reason EGR was added in the late 60's was to reduce Nox and improve highway MPG. A 40 year old technology should be know by every school child

One of first 10 questions on every emissions training/certification test.

Even:http://en.wikipedia.org/wiki/EGR"In almost all cases, a disabled or dirty EGR system will cause the car to fail an emissions test, and may cause the EGR passages in the cylinder head and intake manifold to become blocked with carbon deposits, necessitating extensive engine disassembly for cleaning."