Jay Karolyi

Hi all,

I've been posting on Pelican for quite awhile, and I recently sold my '89 Carrera to upgrade to a 993. From what I can see, Rennlist is the place to be for 993s. After much searching, I found one in nice shape (all books and records, serviced regularly), a good amount of miles but not excessive (81,000) in my price range, and in Midnight Blue, my favorite color!

Does anyone know what 17" wheels these are from? I don't think these ever came on 993s and look more like Boxster wheels. I intend to replace them with RUF wheels, but these wheels have brand new z rated Bridgestones on them so I will wear them out first.

My wife and I drove it through the redwood park in northern CA and had no problems, but on the way home the CEL light came on! I have a code reader and and it reads code 0420 which is "Catalyst System Efficiency below Threshold - Bank No 1". I'm hoping this is an O2 sensor issue. From my research, I understand that the '96 and up 993 has four 02 sensors. I assume this means the car has two cats, with one sensor fore and aft of each cat? Which side (driver or pax) cat is bank 1? How else could I narrow it down?

I reset the light and it came back on about 100 miles later with the same code. I guess this is the official initiation to 993 ownership.

g_murray

Don't be so hasty.
P0420 *is* a bad efficiency code no doubt.

It could be a bad downstream O2 sensor OR the catastrophic converter, on THAT side, is going bad.

Before you start spending bucks -- I would put a can of Berryman's B12 or a can of Seafoam -- (you can get them at an auto store) -- into a full tank of gas and go drive the snot out of the car. On your second and third fill-up, do the same thing. Each time the CEL goes on -- clear it and see if you can see an improvement in the 'time' or 'distance' it takes for the CEL to come back on (with that same code).

My own experience with the P0420 code is that it takes two or more tankfulls of gas (seasoned with Seafoam or B12) for the code to go away. It'll go away - using this method - if it is a 'nuisance code' -- trust me on this -- but if the O-sensor is REALLY on its way out -- then the CEL will never go away -- and therein lies your clue that you may have to include a 'wrench' in your solution to this problem.

Gerry
BTW, Seafoam tends to 'smoke' - so don't be alarmed whereas B12 does not.

dcdude

Yeah, Boxster wheels. They gotta go.

I don't know that code, but you need to come down to Callas Rennsport this Saturday (see other thread). You'll learn a ton at a point in your ownership where it will do the most good!

vjd3

Those rims (Cup 3) were an option in 97 on the 993 ... most people prefer 18" rims or the 5-spoke 17" Cup 2 rim.

The 18" MY02 Carrera 5-spoke rim is a really nice option

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Jay Karolyi

Thanks for the advice so far. I have some Berryman's and will try that...I use it on my longhood 911s all the time. Problem is, I need to smog it to transfer the title. I figure if I reset the CEL just before I get it smogged it won't come on during the test. Would Berryman's cause any problems during the smog test?

About the wheels, my car is an '06 with option code 398 which is:

17 " 5-Spoke Wheels (P205/50ZR17 front, P225/40ZR17 rear)

according to the option decoder. Could these be the original wheels?

Would love to go to the meet at Callas, but Torrance is a long drive and I don't know if I could make it this weekend.

993Dave

Welcome to the OBDII world. You will probably fail your test because, in all likelihood, the computer will not have reset itself yet. I just went through that routine this week. Emission-wise, everything is great, but I failed anyway because the system had not reset itself after cancelling out the CEL warning due to an O2 sensor that is very near the end of its useful life.

FWIW, there are threads here with extensive advice on how to reset the system.

Beyond all that, though, congratulations on finding your new 993!

chris walrod

Congrats on your purchase! Welcome to Rennlist! I am sure you meant 96, not 06. If not, your on the wrong forum

Your in LA? Callas isnt too far, I would think. It will be worth your time, trust me!!

CarreraX

Jay, Congrats on the new car!!! You will love it! you will have the CEL problem fixed asap and be in 993 heaven!!

ste993

Jay, nice car. Congratulations and welcome.

g_murray

+1
Everytime you clear the CEL -- the car's computer system has to 'come to terms with itself'. This is called getting all the readiness codes set to "READY" (do a search on this!) -- and involves specific 'drive cycles' and/or tons of miles added onto your odometer. Read: this takes TIME and EFFORT and FOCUS.

I strongly do NOT recommend you clear the CEL and take it for inspection via the OBD-ii method -- YOU WILL FAIL because the car is not 'ready'. I also do not recommend you take the car for a 'tailpipe test' because - if the cat IS slightly off -- then it'll show up in the smog readings.

Since time is of the essence here, this is what I would do:

i) Let the tank go to 1/4 full and add a can of B12 -- then go drive the snot out of the car.
ii) If you can - attach your code reader and watch the voltage value of the downstream O2 sensor(s). They should 'peak' - if healthy - around .7 volts and go down to 0, then peak again, then drop down to 0. Anything around .4 or .5 Volts is 'low efficiency' territory.
iii) When the tank is nearly empty - add a smidge more gas (to bring it up to 1/4 again) and add yet another can of B12. Again, go drive the snot out of the car and watch the voltage readings.
iv) Everytime the CEL comes on (with the P0420 code) clear it.
v) Keep doing this until you see that both downstream sensors are showing healthy .7 (or better) volts.
vi) If the CEL has not come on - just do a check for 'pending' codes. If there aren't any then leave well enough alone - but this time - fill the car to 1/2 and then go do the 'drive cycle(s)' so as to get the car's PCM/ECM in a totally 'ready' state.

Then take thee to the smog dudes ASAP !!!

Plan B: If after doing 'all this' -- you STILL cannot get the errant downstream O2 sensor to play nice -- then it DOES look like it needs replacing. Not for nothing, but I would have ALL 4 replaced at the same time. Since the wrench is (probably) going to have to disconnect the battery to change the sensors -- you are going to be in a 'virgin' state when you pick the car up.

Yes, that means that AFTER having had the sensors replaced and BEFORE you bring in the car for an OBD-ii test -- you MUST go thru' the drive cycles so as to get the car 'ready'. Yes, yes, it's a total PITA -- but once 'done' it's 'done'.

Many of us have been thru' this -- so we empathize. If you need further advice - just ask.

Gerry

CarreraX

Sure glad that my car is a 95

ZombiePorsche44

I always thought 420 meant it was time to smoke some medicinal marijuana.......LOL......guess I was wrong this time.

ZP44

Jay Karolyi

Gerry,

Wow...that should take awhile to go through two tanks of gas...I'm supposed to submit the title within 10 days of purchase and those are almost up!

Anybody have luck using the CA smog referee as suggested in this Pelican (I know...heresy!) thread:

http://forums.pelicanparts.com/showthread.php?t=260106

Seems too good to be true!

And Mark...shut up! I should have bought yours instead and then you'd be crying right now LOL!

g_murray

Hi,
Yep, I *too* was given "10 days grace" (7 days more than that 'band') :-) ...but I digress...

Because the PO let the battery die (before he sold it to me) - I was put in prettymuch the very same predicament that you are in -- i.e. trying to get the car 'ready' for inspection with the clock ticking.

I could NOT get the readiness monitors to set in the 10 days allowed. So I was 'forced' to drive the car with an -- ummm -- 'expired' smog certificate until she was ready. It was a calculated risk but I felt 'cornered'. Thankfully within a few weeks of driving (and no cop stops) she was 'ready'. I knew this because of the OBD-ii code scanner that I had. BTW, I already had my 'schpiel' ready for any cops that did stop me.

I dropped the car off at the smog station and picked it up that afternoon with its new emissions sticker. Nobody said a word to me about the 'previous' one being gonzo.

I have made every effort (esp. during the winter months) to make sure that the battery NEVER dies on ME.

I might add, that during the 10-days-grace I approached a $tealership about them putting it on rollers and, together with the Bosch hammer, getting it 'ready' for inspection. They quoted me $600 - because it was something that would require a lot of 'personal attention' - and by multiple personnel.

I walked away from THAT proposal pretty darn quick.

What YOU want to do - at this point in time -- is pretty much up to you.
Gerry

zoaatc11

I used the smog referee in August. You have to call the DMV and get an appointment. You just cant have a CEL when you show up for the test. Many OBDII vehicles have issues with the monitors and they know this. They will pass the car without the monitors set. Good luck........