Maggie 2300 Codes P0068 and P0108

[95droptopZ]

So I'm on a nice open road and decide to really get on it, in 2nd gear getting ready to shift into 3rd at around 6000 RPM when all the sudden the stabilitrac light comes on, a CEL and a message on the DIC saying Engine Power Disabled.

As it happens, I was on my way to the dealership for a wheel alignment after installing my lowering springs. I pull off to the side of the road and call Onstar. They run a diagnostic and have me shut the violently rocking car off (very bad stumble or miss in the engine).

They say it is showing a mass air flow code and to have it checked but that after a minute of having the car off it should reset itself.

One minute passes, I start it up and all is fine except my CEL is still on, but she's running good again.

I go to the dealer, have them add a check on the codes to my service.
When they finish, they tell me the CEL was off when they pulled the car in to the bay and it shows the codes P0068 and P0108.

It was late and they didn't have a chance to run them to find out what they are yet. Supposed to call tomorrow and find out, but they believe the codes are for the throttle pos. sensor and the mass airflow sensor.

Searched the forums and only see the P0068 discussed but I'm not sure what it is still.

I installed my Magnuson 2300 2 weeks ago, still have the stock air intake, stock exhaust and am using the "canned" high altitude tune that came in the SCT tuner from Magnuson. The only variation is that the high altitude kit is supposed to come with a 3.6" pulley but as they were backordered, they sent a 3.8" for the time being and said it will just make the car run a little rich with the tune provided.

Been driving her pretty hard the past couple weeks with zero problems but I was on it "VERY" hard today when this happened.

Any ideas out there? Thanks, Marc

[jsharp]

I have heard a custom tune is highly needed on the maggie kits. May be the cause of these problems. I am no expert and barely a beginner but I know on past cars a few parameters on a tune can effect alot of things. I am sure some will chime in

[95droptopZ]

So a quick check on the internet provided this info...
P0068 -Throttle Position (TP) Sensor Inconsistent with the MAF Sensor
P0108 -Manifold Absolute Pressure/Barometric Pressure Circuit High Input

But why it threw the codes and how to fix it?

Maybe a custom tune is the way to go. I was going to wait until I had headers installed for a dyno tune, but now I don't know.

[Will@Apf]

Originally Posted by 95droptopZ

So a quick check on the internet provided this info...
P0068 -Throttle Position (TP) Sensor Inconsistent with the MAF Sensor
P0108 -Manifold Absolute Pressure/Barometric Pressure Circuit High Input

But why it threw the codes and how to fix it?

Maybe a custom tune is the way to go. I was going to wait until I had headers installed for a dyno tune, but now I don't know.

Needs a little more work in the tuning department no biggie.. its sounds like a small "range" issue!..

[Mike TexaSS]

Originally Posted by Will@Apf

Needs a little more work in the tuning department no biggie.. its sounds like a small "range" issue!..

Correct!

[nvpliers]

Thanks all for posting. Helps those of us out that are researching different mod possibilities. This is all good info to know on the tune and potential codes.

[95droptopZ]

Originally Posted by nvpliers

Thanks all for posting. Helps those of us out that are researching different mod possibilities. This is all good info to know on the tune and potential codes.

x2 Thanks all! I'm going to clear the codes and see what happens over the next day or two. I'll report any problems.

[Mike TexaSS]

Originally Posted by 95droptopZ

x2 Thanks all! I'm going to clear the codes and see what happens over the next day or two. I'll report any problems.

Next time you go WOT the p0068 code will return and so will your "reduced engine power"!

[95droptopZ]

So it looks like a series of unfortunate events happened that contributed to this happening.

When I recieved the supercharger there was no instruction manual for the SCT programmer. Instead of contacting Magnuson like I should have, I went to the SCT website and followed the instructions from there.

Well, after having a couple very nice people from Magnuson contact me about the post here, we had to make sure the car's programming was returned to stock, download 2 updates to my SCT from Magnuson, then reload it into the Camaro.

All is fine and several WOT runs later, all problems are gone. The tech I was talking to said with the "canned" tune, a code P0068 should not be able to come up and he believes that the tune never got put into the car to begin with.

I can't argue as it now seems all good. But how did it work for 2 1/2 weeks without any problems whatsoever? And several WOT runs in there to boot!

At any rate, props to Jon Barrett and Andrew Zimmer of Magnuson for picking up the ball and making sure the problem got corrected!

[TATER]

Do you have a boost gauge?

[bumblebeecamaro]

Originally Posted by 95droptopZ

So a quick check on the internet provided this info...
P0068 -Throttle Position (TP) Sensor Inconsistent with the MAF Sensor
P0108 -Manifold Absolute Pressure/Barometric Pressure Circuit High Input

But why it threw the codes and how to fix it?

Maybe a custom tune is the way to go. I was going to wait until I had headers installed for a dyno tune, but now I don't know.

P0108 is caused by excessive voltage readings by your MAP sensor. this is a direct result from the supercharger's boost output. the problem is easily fixable from anyone that knows how to tune via HP Tuners.

talk to Ted Jannetty. the man knows all about this stuff.

[95droptopZ]

Originally Posted by TATER

Do you have a boost gauge?

No I don't, but need to get one. I like ADM's dual setup.

[95droptopZ]

Originally Posted by bumblebeecamaro

P0108 is caused by excessive voltage readings by your MAP sensor. this is a direct result from the supercharger's boost output. the problem is easily fixable from anyone that knows how to tune via HP Tuners.

talk to Ted Jannetty. the man knows all about this stuff.

That is a very good suggestion. I wonder if a dyno tune or an e-mailed tune could work better though. Just a thought.

[bumblebeecamaro]

Originally Posted by 95droptopZ

That is a very good suggestion. I wonder if a dyno tune or an e-mailed tune could work better though. Just a thought.

you could email your current tune to Ted and he can work his magic. then you would install the modified tune and be done with it.

however, the best tunes of course are the dyno tunes. this is due to the fact that most dyno tuners get valuable engine data from a wideband O2 sensor that's used during the dyno session.