Looking to Buy Need Help

[nick71692]

so I am looking at purchasing a 2004 mystichrime convertible. 2 owner vehicle and the 2nd owner barely drove the car. The first owner did some mods, lowered, exhaust, camber plates and what looks like an upgraded pulley (see pics). No tunerwith the car and the car has the service engine soon light on. Starts up and drives fine. The mechanic that normally services the car says the light keeps coming in due to an overboost code. Looking for advice if maybe someone threw on a pulley and never tuned it properly??

My initial thought is to try and return it to stock and start over the right way. His mechanic said a new computer must be purchased for that.

 

[01yellercobra]

Its possible they didn't get a tune for the pulley. I would get a compression test done at the very least to make sure things are good. But go to a different mechanic. If he's telling you that you need a new ECU to start over I wouldn't trust him to check the air in my tires.

If the compression check comes back good and you like the car go for it. But get a tune ASAP.

 

[lunadiver]

Here's what causes the overboost code:

P0234 - Supercharger Overboost Condition The PCM disables (bypasses) the supercharger boost and sets a diagnostic trouble code (DTC) to keep from damaging the powertrain (engine or transmission) during potential harmful operating conditions. Brake torque (brake on and throttle at wide open)
Transmission oil temperature (TOT) exceeds calibrated threshold
Engine over temperature
Ignition misfire exceeds calibrated threshold
Knock sensor (KS) failure or knock detected
Low speed fuel pump relay not switching
Check for other diagnostic trouble codes accompanying the P0234 or check appropriate and available PIDs related to above possible causes.

Since we dont have a knock sensor you can rule that one out.

Sent from my SM-G965U using the svtperformance.com mobile app

 

[nick71692]

If it does have a pulley on it how can I accurately get a good tune on it or would a tuner just go with an off the shelf map, get data logs and adjuat from there?

Thanks for providing the details on the code. The current owner has been driving the car like this for 6 years. Now in that time hes only put 4k miles on the car. I would definitely start driving it more so I want to make sure its reliable.

 

[Goose17]

First off, you’ll love Mystichrome! It’s freak’n amazing!

Secondly, be careful not to end up with someone’s problem child. Get a health check of the motor as mentioned above. If it’s still healthy, use the check engine light to negotiate a lower price and pull the trigger. Then either return the car to stock and get the tune reflashed at a Ford dealer or work with a reputable tuner and get it dialed in for what’s on the car now.

Stay out of boost until you get it straightened out.

 

[hotcobra03]

I have had po234 on a stock setup.

Mine was tmap plug wasn’t seated

This sensor is on intake drivers side rear under egr tube

 

[nick71692]

Thanks Goose and hotcobra. Thats probably what i will do. I feel pretty good about it given he has owned it six years and also has an 18 gt 350 and 14 gt500. Its not his only car and has a bit of money to take care of them. He doesnt drive it anymore because he said the gt350 makes the cobra feel old and outdated which I believe having a 15 GT with performance pack as well. These older interiors are terrible

 

[blownfox]

As other said compression and or leak down test.

I would check to see if there is a chip in the ECU. I'm wondering if they tried to re-tune the car but cant because the ECU is locking them out. I had that issue when I bought my car several years ago.

 

[01yellercobra]

If it does have a pulley on it how can I accurately get a good tune on it or would a tuner just go with an off the shelf map, get data logs and adjuat from there?

Thanks for providing the details on the code. The current owner has been driving the car like this for 6 years. Now in that time hes only put 4k miles on the car. I would definitely start driving it more so I want to make sure its reliable.

A tuner would start from scratch. Most probably have a tune already written for your mods that's pretty close.