Failed smog as stated in a recent post. Took it to shop...conclusion..."found that rear exhaust manifold bolt is broken, causing exhaust leak. Leak is allowing air to enter the exhaust...causing hashy pattern and poor fuel control" Does this make sense? I took it in to figure out why it was running rich. Am I missing something here (besides my $75). I did have them replace the O2 sensor. I don't get it. The car runs very strong but cannot pass smog. These f*#@ers didn't help me any. Thanks for your help!

https://www.thirdgen.org/techbb2/sho...hreadid=257197

 

*nm*

 

ever had your catalytic converter replaced in the last 10 years? I was determined to do everything under the sun to not have to replace mine when I got the car, but after I did a full tuneup including O2s, and I cleaned out the EGR passages, it still failed (not by too much, but still enough).

So I broke down, went to MIDAS, had a coupon for a 99 dollar catalytic converter, they didnt even charge me labor (gave me a really really restrictive and small cat though) and I passed emissions with flying colors.

The shop sounds like they ripped you off really. 75 dollars (an hour of labor i'm guessing) to tell you that you're missing a bolt in the headers? well for an hours worth of work to tell you that they should have plugged up the hole for you lmao.

 

lyllibido, an exhaust leak near or in front of the o2 sensor can cause the ECM to think the motor is running lean because of the
extra oxygen drawn into the exhaust. if your lucky, the bolt is just missing & not broken off. looking at your other post this could very well be your problem. also, bumping the timing back a little will drop the HC some & sometimes drop the CO alittle bit. judging from the readings, it looks like your cat is probably fine, did they check it? something to remember, once the exhaust leak is repaired, some other problems could show up.



sellmanb, not ragging on you but, sometimes i wonder just how much of a cut in pay people who work in other industries would take when someone thinks they charge too much for the work they do. shops charge for diagnostics, as they should. there are plenty of shop where they have 1 guy who does almost nothing but diagnostics, should he do this for free?

 

I wasnt saying that he should have gotten a free diagnostic, I was simply saying that it shouldnt have taken the diagnoser an entire hour to figure out that a bolt was missing in the exhaust manifold.

I completely understand that they should charge for diagnosing a problem, hell I've considered going to a shop to have them just diagnose all of the problems with my car to make it simpler for me (but decided against it since I want to learn about my car from personal experience).

By no means am I saying this all with a "mean" tone, but I just think what I wrote was misinterpretted. Dont get me wrong, I think that they should pay for diagnostics, I just didnt think that they should have taken an entire hour to find an exhaust leak as simple as that one.

 

sellmanb, i think i did kind of take it the wrong way, sorry for that. im still alittle pissed at GM for leaving out some need to know info on a caddy blower motor.

alot of times the hardest problems to find are the minor ones. i have had some that had such a small exhaust leak but without the noise to let you know its there but it was enough to cause a noticeable drop in gas mileage.

the way his car was checked probably went something like this, first they pull it in & hook the scanner up & pull codes & check the data while they are waiting for it to warm up, once warm they did a base line. next, checked timing, primary & secondary ignition patterns. having found nothing at this point they look for vacuum leaks, enrich the fuel mixture & then make a vacuum leak to see how it responds to the changes, somewhere during all this they did a cranking compression test, a cylinder balance test, checked the fuel pressure, checked the air injection system, checked the cat for inlet & outlet temp difference, did a injector leak down & drop test, & checked for any TSBs. as you can see, there are quite alot of things to check, so i can see it easily taking up an hour & then some.

again, sorry for misunderstanding you.

 

Check out MPG Technologies, www.getmorempg.com

They have an emissions treatment kit that will substantially lower both HydroCarbons and NOx. In addition to cleaning the pistons and cylinders their product treats the metal with a dry lubricant that will decrease friction, improve gas mileage and increase horsepower.

Official Test Results
Reduced Friction 12.6%
Improved Horsepower 15.5%
Increased MPG 17.5%
http://www.getmorempg.com/pdf/uou.pdf

Approved by the Federal Aviation Administration for use in aircraft, MPG Technologies products have been tested by the US Department of Energy, Franklin Research Group, NASA and Consumer Digest.

"We were skeptical at first, but it turns out that the product does exactly what the manufacturer claims."
Consumer Digest

http://www.getmorempg.com/testing.htm MPG Technologies backs up their claims with testing and offers some revealing information on other products on the market http://www.getmorempg.com/compete.htm

As the inagural primary sponsor of the Long Beach Gran Prix under the LubraLon label their treatment set the pace for the industry. Emissions and fuel treatment significantly reduces toxic emissions. The transmission and gear box treatment can save thousands of dollars on rebuilds.

Racing teams have used a variety of MPG Technologies products! The engine treatment has been tested worldwide by universities, military, government and independent test facilities have shown an increase in Miles Per Gallon, reduced friction, and decreased heat and wear to extend the life of your engine. Test have shown mileage increased by as much as 5 miles per gallon, with climbing fuel prices an increase in MPG is worth checking out!

They also have products for Car & Truck, Boat, Plane, Small Engine, Motorcycle, Heavy Equipment, Compressors and a variety of other mechanical engines.

 

Well to steer you away from that blatant display of advertisement.... there is also a product called "Guaranteed to Pass" it can be found in your auto parts store like Schucks, NAPA, Advanced Auto, etc...

I tried it on my car, but got minimial results (needed a new cat), I know there have been people who use this product and it works for them perfectly, and then there's people who use it and gain nothing from it. If using this type of product helps your car then you're

A) Wildly not stock
B) Using old fuel
C) Using too low an octane fuel
D) There's something that might be wrong w/ your car in the first place that's rather small.

If I were only like .05 away from passing, I'd give the Guaranteed To Pass a try, but that would be at desperate measures since it's like 10 dollars for a quart.

Get a bolt in your exhaust mainfold and give the emissions test another whirr.

Also, I'm pretty sure that advertising in these forums is against the rules of the board?

 

There's no need to pay $10 for that stuff. Just run the tank down to about 5 gallons of gas and put in a quart of naptha (available at many hardware and paint stores). That will warm up the converter a bit more and lower HC. After the emission test, go fill the tank to dilute the naptha. BTW, and unless something changed, that naptha can't be detected when testing emissions.

Next time I'm in a auto store, I'm gonna look for that stuff and hopefully the can will disclose what's in there.

 

Whats naptha?

Probably ethenol. Its already used in gasoline in many areas with high pollution.

 

Noppers, ethanol (aka grain alcohol, ethyl alcohol) and naphtha are not the same. Naphtha is just another solvent; toluene, MEK, laquer thinner, etc are other solvents and are used for different things. The local True Value near me carries naphtha.