Litespeeds

When I bought my 88' 944, the owner took it in for smog for transferring ownership title and it failed the NO but passed the HC and CO. The car has a chip that advances the timing and he didn't take it out. Anyway, when I bought the car, I told him that I would deal with the smog issues if he would lower the price by $200 and he agreed since it wasn't worth his time to change out the chip and take the chance that the car still won't pass.
The original owner told me that the car has to use premium unleaded 91 octane gas and also add a bottle of octane booster because it pings. I didn't really notice any pinging so when I filled up gas, I decided to go with only 87 octane. I immediately heard some pinging when I gave it more than 1/4 throttle or when the rpm's went past 3K. I realized that older cars are different than the newer cars that have knock sensors and other things that will prevent the car from pinging. To make a long story short, I switched out the performance chip and put the stock chip back in and now there is no pinging at all even with the 87 octane gas. I know that the manufacturer recommends 91 octane but I figure if I don't drive this car hard, I can get away with using cheaper gas. I will definitely use 91 octane when I run it at the track.
The car passed the smog test with flying colors with the stock chip.

Since I have you guys here, do you think I should put the performance chip back in to gain a few extra horsepower or just keep it stock when I run at the track? Is reliability much safer with the stock chip over the performance chip?

bloodraven

Can't say much as far as the chips go, but I find it hard to believe that you passed the smog test. If I were the inspector and saw flying colors coming out the tailpipe...I would be kind of suspicious

michaelathome

From what I have read a chip in the 944NA doesn't really do much other than re-map the curve. If it was an easy swap then go back to the chip and pay the $ at the pump to keep the knock away. If you don't mind the change I would stick with it.

I think that there might be something else that is causing the knock though. I am gonna take a chance and say pull your plugs label them and set them aside. Drop a new set of copper plugs in there and drive on them for a while. It will cost you less than gas at this point. Pull those, clean them and put them back in and drive some more with the chip keeping the same grade fuel.

Once again it seams that #4 tends to run lean and I would guess that is your problem.

Try getting your injectors cleaned/rebuilt or replace them w/new (OUCH did I say that?)

Anyone else?


Michael

KuHL 951

I've passed smog twice here in Cal. with my Welt chips left in. The timing shouldn't be advanced at all in the 15 mph and 25 mph run required for smog. 2250 rpm is as high as he took it to hold 25mph. Most of the mapping on the Welt chip is done well above this range, mine even spit raw gas at onset of hard boost. I'll have to see how the new Vitesse chip tests out next time although many people have had no issues at all.

By all means put the chips back in, the HP gain is quite a bit more than a few.

michaelathome

Steve, I think that he is running unboosted

I would suggest the same though if I thought he was

Michael

brad-cam

My 951 is due for a smog test next month - I'm a little nervous about it, running the Guru chips. Will the visual test pass ok if the only changes from stock are the Reliaboost MBC, 3.0 bar FPR and Forge BOV ?

Techno Duck

My old 924S was impossible to get pass smog. NOx was IMPOSSIBLE to get any lower than 10-40 over the limit.

My 944 is in much better shape...infact im curious to see if this car would actually pass inspection with the FRWilk chip on and off. But my last inspection i had it done at my fathers friends place. Lets just say i have equal emissions to that of a 4-cylinder Toyota Camry.

PEvans

Litespeed, What is the mileage on your 88 944?

My 1986 951 passed the now more rigorous CA Bay Area smog check with the NOx test by a whisker last time, and I am following all the smog threads with interest to see what the real key is to passing, since I have to do it again in about 1 1/2 years.

I think the challenge for 951s is the NOx. Many of the posts for folks with trouble with HC and CO seemed to tie back to the fact that the car was not not tuned or running right. I'm not a big wrencher, and I always have a major service done just before the test. My HC and CO numbers are up since the car was new, but still comfortably below the limit. NOx, tested for the first time in this last test, is JUST below the limit.

I'm beginning to think the real key is the catalyst. I don't think the chips and mods matter as much if the car is running the way it is supposed to. That's why I ask about Litespeed's mileage. I'm not sure how long these cats are supposed to last, but mine has over 200k on it. Unless I hear of some magic fix here over the next year I will have mine replaced before my next test.

Brad-cam, my suggestion is that you make sure your car is running well. Also, make sure both your low-speed and high-speed fan settings are working (the car will sit there running at high RPMs on the treadmill and the engine can get very hot, which all you chemists know boosts NOx formation in the combustion). See Clark's Garage for a test. <http://www.clarks-garage.com/shop-manual/cool-01.htm>

Some people suggest driving the car on the freeway for a while just before the test so the catalyst is hot. Make an appointment so you know the car won't sit and get cold.

If this is the first treadmill test for this car I would say do these simple things and go for it. If you already know it's doubtful, replace the cat.

If anyone disagrees, I am eager to hear.

bearone

it passed with "flying colors", they weren't coming out of the tail pipe.

87951

Litespeeds

The car has 154K miles and it is a 944 NA. I am not sure if the cats are original or not since I just bought the car. I drove the car on the freeway and went straight to the smog station and had the car idling for about 10 minutes before he ran the tests. The mechanic did rev up the engine to around 3K for about a minute before he started the testing to make sure the cats are hot.

When the aftermarket performance chip which advances timing was on the car, it still passed the HC and CO but failed the NO. Maybe it is time for me to change out my spark plugs and give it a good thorough tuneup. That might have helped too. Maybe I didn't have to switch out the chip.

Ben Z.

Who makes the chip? If you don't know, I'd say just leave it out. The NA chips (even the very best ones) don't really do that much good. And if it was a crappy map, then there was nothing wrong with your car besides the chip.

bearone-
Posts like yours keep me coming back to rennlist! Wow.

cjeckert

Every time i've taken mine in for smog i havent been anyware close to the limits, the tester last time told me some of the new honda civics dont test as low as my car.