Smog check time. Higher octane helps?

[wrcsixeight]

With 8 days left till my registration expires, California finally decided to send me my documentation for rego renewal. It is also 30$ more this year than last, IIRC.

My last test 2 years ago, I was running a bit high on the hydrocarbons, but still passed. They are supposed to check the timing, but when the tech did not see a battery in my engine compartment, he just went back to the computer and typed in 10 btdc, what it is supposed to be. I later checked it and found it was at 18 btdc so it is a good thing my engine battery quit and I was using my under floor house batteries as my engine battery otherwise I would have failed the test and wasted 65$.

Anyway, I am theorizing the high HC numbers were due in part to the advanced timing, and an out of whack Coolant Temp sensor which I have since replaced(along with the whole cooling system)

My one friend says that I should go to the test with 91 or higher octane fuel in my tank. I always buy 87 as I never get any pinging. Will higher octane lower my CO/NO/HC numbers?

I've also recently tried some MMO in my gas for the first time with the last 8 gallons. The engine seems a little rev happier in neutral, but perhaps less power too. I kinda guestimated 4 ounces of MMO and the amount of fuel in the tank at about 10 gallons but perhaps I used too much.

Will having MMO in the tank during the smog test negatively or positively affect the Smog numbers?

I have throttle body fuel injection, 25 K miles on a magnaflow catcon, and 35k miles on the rebuilt 318 and really would like to pass this test with flying colors.

Thanks.

 

[Chris142]

Fuel octain won't make any difference. A couple bottles of Isoprople alcohol will clean it up some and so will an oil change right before the test.

 

[ComfyShorts]

 

[HTSS_TR]

Make sure you have a good drive about 15-20 miles before the test, otherwise the engine will run rich and high HC is the result.

 

[ltslimjim]

^This. Though, ironically my mechanic recommended getting some premium mixed as well, back when the VX was originally have problems passing emissions. It passed with a bad 02 sensor, too!

 

[Malo83]

A good tune up new filters and fresh oil are a must, 91 won't really matter but run it hard and fast on the highway and throw in a bottle GTP, and you should be good to go, use it in my 83 Silverado which hasn't failed yet

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[ltslimjim]

^You know, I tried that when I first bought the Civic but no dice, other issues had to be corrected.

Didn't think to double my money back from them, though. lol.

I wonder what is in that stuff anyway?

 

[Quest]

Originally Posted By: Malo83
A good tune up new filters and fresh oil are a must, 91 won't really matter but run it hard and fast on the highway and throw in a bottle GTP, and you should be good to go, use it in my 83 Silverado which hasn't failed yet

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we have to take ours in for annual smog checks too (unless yours are between 1993 and 2003/early 2004, which is to be checked every 2 years). one of my client's vehicle, which was known to have high HC issues (OBD-2, Toyota Pasaeo) due to weak cat, tried CRC guaranteed pass, and it didn't pass (wasted 48 bux with a failed notice). I tried one of the old mech's trick and managed to get it through a borderline pass which was good for 2 yrs. 1.8yrs down the road the car was stolen and was never recovered again.

IMHO this CRC guaranteed to pass is a waste of money, esp. if you have an engine that is burning oil or HC due to weak cat. Yeah, I know it guarantees you with money back but filing for money back wasting additional time and postage and then wait for a few more months in-vain just to get the bottle of elixir + inspection fee back? Whatta waste of my time?

(I have to take a few hours off of my work time to bring vehicles through smog test, and that is time/opportunity cost lost on my end and in the end: it's a sunk cost that I can never recover from CRC.

Don't waste time on these OTC stuff. IF your car fails smog test, something needs serious attention and at that point you should decide whether you want to sink some serious mullah to get it fixed properly, or you'd rather trade it in for a better vehicle.

Q.

 

[Stu_Rock]

Originally Posted By: wrcsixeight
With 8 days left till my registration expires, California finally decided to send me my documentation for rego renewal. It is also 30$ more this year than last, IIRC.
It should be considerably cheaper this year, since the vehicle license fee rate went down. The renewal notice was late because the legislature hadn't decided until last week whether or not to extend the prior high rate.

It sounds like your van is running well. Further, it sounds like you have made repairs that should improve its performance since the last smog check. I would just take it in and see what happens. Maybe look for a shop that advertises "pass or free retest" if you are anxious about it. For the fuel, I doubt octane really matters.

Also, check to make sure on your last report that the HC is actually high relative to the standard. On my Dodge van, two of three times I had it smogged, the MAX values on the report were the ones for passenger cars, not light trucks. If you hunt on BAR's website, you can find what the actual "cutpoints" (search for that word) are for a 1989 light truck. Then compare to your old report.

On the subject of CRC's G2P product, I think it's a large dose of PEA. It sounds good for cleaning valves, but I don't think it would do anything for a vehicle that has actual problems with its engine or emissions equipment.

 

[ComfyShorts]

Quote:

Don't waste time on these OTC stuff. IF your car fails smog test, something needs serious attention and at that point you should decide whether you want to sink some serious mullah to get it fixed properly, or you'd rather trade it in for a better vehicle.

Q.


Wait...so you mean mechanic-in-a-can won't fix my valves, rings, vacuum leaks and weak catalytic converters? But it says its guaranteed to pass so it must be true.

 

[wrcsixeight]

Thanks for the replies.

My engine does run incredibly smooth, any resorts like "mechanic in a can" will not be needed. I believe that GTP stuff's directions say you got to run it through a tankful of gas before the test. It's not as if you put that stuff in your tank and your engine runs 50% cleaner.

My real only worry is the Cat. It is not too old, but I was running slightly rich for a while (before I backed of the timing and replaced the CTS) and I guess that uses up more of the catalyst.

I also hear Bosch O2 sensors do not really work that well with Mopar ECM's, but the first 2 tests I passed with great numbers with bosch installed.

I will not be changing the oil before hand, it only has 1k miles on it, and the other tricks like making sure it is at full temp before the test are well known to me.

I'll post the results/numbers when I pass.

 

[Quest]

Originally Posted By: ComfyShorts


Wait...so you mean mechanic-in-a-can won't fix my valves, rings, vacuum leaks and weak catalytic converters? But it says its guaranteed to pass so it must be true.

Right!! Very funny indeed.

I've been fixing cars (was certified 20yrs ago as a mech) on and off for 2 decades, and none of the OTC mech-in-a-can ever work to my satisfaction or meet my expections consitently.

I did have success when using some of the rather controvesial cleaners (AutoRx, LC20, etc.) but then again: I'm fully aware of what the exact mechanical problem was, and use products specifically targetting the problem areas (and achieved the results). Ditto with some fuel additives that contains PEA.

Q.

 

[friendly_jacek]

The only chemical things I'm aware to decrease HC is alcohol in gas and/or high weight PIB polymers (ie Viscon).

Clean combustion chambers wouldn't hurt, so a couple of tanks of techron in gas before.

According to some, TCW3 1:500 helps, but I'm not completely sure of that.

 

[Loobed]

Originally Posted By: Malo83




That stuff has a lot of PEA. It is similar to Regane, Techron, Redline SI-1, or Amsoil PI. A mechanic friend said he had a car that barely failed smog. He put a bottle of GTP in the tank and drove the car hard for a week. The next week he ran the car through the smog test and it lowered the emissions by almost half. The car was used and abused (He buys trade-ins from the dealer than fixes them up and sells them). The GTP wont do miracles, but if the engine was treated like junk, it can help.

 

[dailydriver]

Originally Posted By: Quest
Originally Posted By: Malo83
A good tune up new filters and fresh oil are a must, 91 won't really matter but run it hard and fast on the highway and throw in a bottle GTP, and you should be good to go, use it in my 83 Silverado which hasn't failed yet

Uploaded with ImageShack.us


we have to take ours in for annual smog checks too (unless yours are between 1993 and 2003/early 2004, which is to be checked every 2 years). one of my client's vehicle, which was known to have high HC issues (OBD-2, Toyota Pasaeo) due to weak cat, tried CRC guaranteed pass, and it didn't pass (wasted 48 bux with a failed notice). I tried one of the old mech's trick and managed to get it through a borderline pass which was good for 2 yrs. 1.8yrs down the road the car was stolen and was never recovered again.

IMHO this CRC guaranteed to pass is a waste of money, esp. if you have an engine that is burning oil or HC due to weak cat. Yeah, I know it guarantees you with money back but filing for money back wasting additional time and postage and then wait for a few more months in-vain just to get the bottle of elixir + inspection fee back? Whatta waste of my time?



SAME with the 'Cataclean' stuff.

They claim it will clean/rejuvenate your catcons to the point of turning off the SES/CE lights, but when it DOES NOT, you then must go through inspection and FAIL (with ALL OF THAT subsequent bother/hassle/cost/time), and send in that documentation in order to be reimbursed!!

 

[tom slick]

Advancing the timing will lower HC but can raise NOx.

If you are borderline fail on HC use 1/2 gallon of denatured alcohol in 12 or so gallons of of gas. It'll drop it just below passing, I've done it myself. You can buy it at the hardware store.

 

[wrcsixeight]

Well, I passed!

I wish the numbers were better, but at least the HC numbers were lower than 2 years ago. I cannot find that test paper, but I remember I just passed on the HC in '09.

My test in '07 was by far the best. I had just driven cross country in 3 days, changed the oil, installed a new air pump, and all the numbers were about 10 times below the maximum allowed. I wish I could find that test result.

I Did not really do anything special to get a passing result. I did put 5 gallons of MMO free 91 octane on top of about 4 gallons of MMO'd 87 octane. I backed off my timing to 9 BTDC(Listed at 10), and visually verified my EGR valve was operating.

The Tech told the customer before me(who failed, '02 BMW) to run a bottle of GTP through the tank, then fill it with premium 91 octane for the next test, for whatever that is worth.

I was able to find my first Ca smog test result from 2005. My CATCON was just a few months old at the time.

Looks like they lowered the allowable limit for CO.

Feel free to comment.

 

[Stu_Rock]

Congratulations on the pass. I thought it was going to work out for you.

It is running a little rich. Maybe the oxygen sensor is on its way out? The fact that both HC and CO are elevated suggests that the combustion reaction is occurring, but without sufficient O2. CO2 seems a hair low, which corroborates.

The O2 reading seems high for rich running, but this van has air injection, so it doesn't really mean much.

 

[wrcsixeight]

Thanks.

I really wanted to install a new throttle body gasket kit and an NTK o2 sensor, but for a welcome change, I've had too much work, and too little time. And back when I had too little work and too much time, a new o2 sensor was not on the list of priorities.

I keep seeing different reports as to which was the oem provider for mopar. NTK or denso, or was it delphi?

 

[NHHEMI]

I have seen the CRC stuff help in a borderline vehicle.