epj993

Driving home last night I got the dreaded CEL. I was just cruising 70-ish on the freeway and it appeared. I've got a 1997 C4S with about 50K miles.

I picked up a scanner and it returned code: P0410 - Secondard Air Injection System Malfunction. BTW, it took me a few minutes to deduce that the immobilizer must be deactivated first to get access to the OBD port.

Based on these boards and the SAI posts, I'm thinking I should start by replacing the SAI check valve. Just wanted to confirm that I am heading in the right direction? Any other info would be appreciated.

Thanks,
Eric

dhicks

If you have not replaced that recently it is a must......reset your codes and see how long it takes before you get the CEL come on again.....the funny thing is that everybody say the SAI only operates for the first 30 secs on cold starts so why does the light come on when you are driving and the car is hot....mine does this too....not on start up....and sometimes mine will go off if I have been cruising for a while with it on....I just do not fathom it???

Father of 3

When you reset, at least with my scanner, all you do is turn off the sensors (don't know if this is the right word) - they do not read until reset. These sensors are reset through normal driving over time, or by going through the readiness reset routing as documented on Rennlist. Once the sensors are reset, your light will come back on. I know of no other fix for what ails you than to have the passages cleaned out ala p-car.com DIY or by a shop like Hergesheimer. The shops usually charge around $1k for this procedure. I guess the $64k question is, are you burning oil?

epj993

I don't think I'm buring excessive oil. No smoke on startup. I purchased the car with 48,500 miles and am now at ~50,100. When I bought it I was at about the halfway mark on the dipstick. After 1,200 miles more, I added a quart - so I don't have a solid baseline yet. Currently, the dipstick reads full. Based on this, I'd guess I'm burning approx. 1qt every 1,500-2,000 miles which is within limit.

Are you sure about turning off the sensors? I think the sensors remain active but you're clearing the error code. If the issue is not resolved and the readiness reset is preformed, I would think the CEL would light. If the issue is resolved, I would think the CEL would stay off.

Hope I'm not missing anything with that last paragraph. But, I am planning to do the p-car DIY on this. I just need to hone my wrench forging skills ;-o

-Eric

jford

I will chime in and tell you that when I got a CEL for the same issue, mine woudl come back on relativley quickley after resetting. That is to say I did not need to go through the drive cycle for the sensors to come back on line. I do know what the cycle is becuase I needed to show 'ready' to go through NJ emmisions.

That being said since I have started to track my car...hard....I have never again got a CEL. I remember when I got my PPI asking the tech (recomneded by many here) about the CEL. He asked what I was going to use the car for ...I said recreational street driving and about 15 to 20 track days/yr. He told me not to worry about it. Of course I got the CEL 2 days after getting the car home but, like I have said not since driving the car hard on a regular basis.

Just my expereince.

Jamie

dhicks

If you got your CEL after getting the car home....isnt that suspicious....the PO must have known about this.....I got mine about three weeks after I bought the car and although told cast iron no way...I am still suspicious about the CEL coming on so soon after buying???

Father of 3

Again, my caveat being my reader is a Kragen $69 reader. When I've reset a CEL and try reading right after, it shows sensors are not reading anything - not ready to read. After driving around a bit and reading again, most sensors reset and light came back on. Just my experience that my reader did not just turn off light but reset sensors or rather turned them off and back on, just as if I disconnected the battery.

Father of 3

Simple way to find out is to reset and try reading again. On my reader, the various sensors flash if not reading and stay on if they are reading. Try yours. Good luck.

trojanman

I believe the more sophisticated sensors will give more detail as to the specific location and degree of blockage, if any... call Laura at Hergie's and ask her. I know they were able to determine where my blockage was before even tearing the engine apart.

Bull

I too saw the "dreaded" SAI CEL a few years ago. 25-30 track days a year and I haven't seen it again for 3+ years. I have had several Factory (in the factory) trained Techs tell me that the type of driving you do directly effects this issue. "Sitting in bumper-tobumper, slow moving traffic is the worst".

epj993

Very interesting - Father of 3. I'm just going to have to learn by experience, I guess.

Bull, I have no problems driving hard - in fact, that's what I do! But I can't speak for the PO.

Related to this, I just picked up a new SAI check valve. When I asked the parts guy for it, he said: "Do you want both of them?" Checking the exploded view on his screen, there is also a "shut-off valve" a little upstream from the SAI valve. I'm wondering whether this is also a problem and should be replaced as well.

Since I'm not sure exactly where the shutoff valve is located in the engine compartment (I couldn't tell from the exploded view), I thought I'd might remove & examine it once I get in there and it's accessible.

Anyone know anything about the "air injection shut-off valve"?

-Eric

jford

Eric,
I think my PO babied the car as I think many do. It would be interesting, for example, to see just how many people go to redline (yes I know the peak tourque/hp is just below that) and how often. People will advertise there cars as 'woman driven' as if to illistrate the car has been babied (no offense to C Boyd or any other woman P-car driver). I think there many drivers (maybe not on this board however) that treat thier cars like some sort of museum piece. They don't like that, the cars that is.

Jamie

epj993

Jamie,

I agree. Porsche's are great cars, but quite expensive. I'm 45 & just got my first after 30 years of lusting & waiting. I'm in So Cal. and you can't count the number of 911's you get stuck behind because the retired driver (no offense to anyone) doesn't want to break 2,200RPM.

It's really backwards when you think about it. $5,000 Geo Metros getting redlined by drivers, yet a true race-breed idles along.

Well, I'll have none of that!!!

-Eric

Terry Adams

Which is why I could never agree with the saying "Youth is wasted on the young." Bought my first Porsche at 44 and have been redlining regularly ever since.

Lorenfb

"When you reset, at least with my scanner, all you do is turn off the sensors (don't know if this is the right word) - they do not read until reset. These sensors are reset through normal driving over time, or by going through the readiness reset routing as documented on Rennlist."

When a DTC (diagnostic trouble code) is reset via a scanner, the sensors are NOT affected.
Reseting the DTC also resets the readiness states which indicate the self-test state
of the emission system. Once this occurs, the vehicle must be driven to again SET
the readiness states.

To state that driving at high RPMs will reduce the likelihood of a SAI CEL is misleading.
If the engine has a valve guide wear problem, this will only accelerate the SAI problem.

For more SAI info, check here ( www.systemsc.com/pictures.htm ).
For OBDII info, check here ( www.systemsc.com/codes.htm ).