New Tune on car, problems

[kenthompson]

I got the car running last week, but so far I have the following error codes

55 – ECM error
63 – Right bank O2 sensor lean exhaust indicated
64 – Map sensor circuit signal voltage low (High vacuum indicated)

The first time it turned on the code was yesterday after getting on it through third gear (good heavens!!!), then it turned out after I shut the car down and restarted it after an hour (figuring it was a hard code and wouldn’t erase) but the light was out. Drove it home without getting into the throttle. This morning, it turned on the SES light driving down the freeway at cruising speed (70 MPH).

I haven’t cleared the codes yet (via disconnecting the battery or pulling the ecm fuse), but I would like to get the car emissions tested and for that the SES light needs to be out.

Ideas?

[jonszr1]

does the car have the stk prom in it . you might ck the right o2 sensor and see if it has come loose . have you put headers on the car?

[kenthompson]

does the car have the stk prom in it . you might ck the right o2 sensor and see if it has come loose . have you put headers on the car?

Sorry, I copied the same text as I email to Mark Haibeck and pasted it here.

Mark's tune with secondary removal (thus the no full throttle part, car would go badly lean), no I don't have a factory PROM to install.

Yes, it has a set of Haibeck's shorty headers. I doubt the O2 sensor has come loose but I guess it's worth checking.

[-=Jeff=-]

start with lower code # first, then move to the next

make sure the PROM is fully seated in the ECM.. have the battery disconnected to clear codes.. then try again, if 55 reappears it could be a bad burn or checksum in the PROM and might need to be re-burned

I have had that happen numerous times, with the PROm for the car and with stuff at work.. it happens

once 55 is fixed, then see if the others return

[kenthompson]

start with lower code # first, then move to the next

make sure the PROM is fully seated in the ECM.. have the battery disconnected to clear codes.. then try again, if 55 reappears it could be a bad burn or checksum in the PROM and might need to be re-burned

I have had that happen numerous times, with the PROm for the car and with stuff at work.. it happens

once 55 is fixed, then see if the others return

K, I tried reseating the PROM. Seemed to go a little further in the socket and snapped in solidly. We'll see if that fixes the issues.

[jonszr1]

wow hope the seating of the prom works

[Jeffvette]

I got the car running last week, but so far I have the following error codes

55 – ECM error
63 – Right bank O2 sensor lean exhaust indicated
64 – Map sensor circuit signal voltage low (High vacuum indicated)

The first time it turned on the code was yesterday after getting on it through third gear (good heavens!!!), then it turned out after I shut the car down and restarted it after an hour (figuring it was a hard code and wouldn’t erase) but the light was out. Drove it home without getting into the throttle. This morning, it turned on the SES light driving down the freeway at cruising speed (70 MPH).

I haven’t cleared the codes yet (via disconnecting the battery or pulling the ecm fuse), but I would like to get the car emissions tested and for that the SES light needs to be out.

Ideas?

Ken, 55 is not a ECM error code. 55 is a fuel lean monitor. Which will either be a bad fuel pump, relay or ground/connection. Check your fuel pressure while driving.

Code 64 is the right O2 sensor going lean, which makes sense with the code 63, and the 55.

[kenthompson]

from gmtuners.com code 55 said it was ECM error. They are apparently wrong.

I did notice that the fuel pressure was only 42 running and 42 KOEOFF. Might have to pull the fuel pumps and check the strainers....

Or more mods with Walbro......

[Jeffvette]

from gmtuners.com code 55 said it was ECM error. They are apparently wrong.

I did notice that the fuel pressure was only 42 running and 42 KOEOFF. Might have to pull the fuel pumps and check the strainers....

Or more mods with Walbro......


They also seem to think the LT5 was made from 91-94.

Code 55 is only set using the secondary system under WOT.

[kenthompson]

They also seem to think the LT5 was made from 91-94.

Code 55 is only set using the secondary system under WOT.

Makes sense that Mark took the secondary system out of the tune (error codes and such), but didn't take out the lean codes.

And that's when it happened, when I got on it at WOT.

[XfireZ51]

Ken,

What do you mean "Marc took secondaries out of the tune?" Do you have secondaries operative? You can't take error codes out. The calibration is setup so the error codes are not set.

[kenthompson]

Ken,

What do you mean "Marc took secondaries out of the tune?" Do you have secondaries operative? You can't take error codes out. The calibration is setup so the error codes are not set.

I mean Marc turned the error codes for a non-functioning secondary solinoid off, and I removed the equipment from the car. His instructions were to always run the car with the valet key on, and no WOT operations if the SES light was on. Apparently, the tune is setup to activate the secondary injectors only if those two conditions are correct (given all the other parameters such as TPS settings and such are inside their ranges), and if not, there is no protection from the motor running lean if the secondary injectors do not activate.

Car runs smooth on acceleration and part throttle applications, so something must be correct. And I know it's a lot cleaner under the plenum now.

[XfireZ51]

The symptoms you describe are nearly identical to the ones I ran into last summer. Same codes. It got fixed by installing new fuel pumps and new strainers.
My calibration is setup like yours where the secondaries are ON all the time except for idle. Marc told me how to change the
calibration.

[kenthompson]

The symptoms you describe are nearly identical to the ones I ran into last summer. Same codes. It got fixed by installing new fuel pumps and new strainers.
My calibration is setup like yours where the secondaries are ON all the time except for idle. Marc told me how to change the
calibration.


Based upon my further testing last night and talking to Jeff Flint, I'm rapidly coming to the same conclusion. Pump pull scheduled for later today (hopefully)!

[kenthompson]

So the code 55 hasn't come back, I consider it a dead issue.

But now it's issuing code 63 and 64 regularly.

The fuel pressure seems to be functioning ok. I got the FP gauge (autometer 2663) on the a-pillor to work again, along with the air-fuel ratio gauge (autometer 2675). Fuel pressure is fairly reative after putting fresh fuel in the car this evening. Fuel pressure is 42 PSI at an idle or light cruising. Upon acceleration, it immediately goes to 53 PSI.

The A/F gauge however, is a different story. It rocks back and forth from absolute lean to rich rapidly. Could be a loose connection on the connector to the o2 sensor, or could be the o2 sensor on both sides. The car was running very rich for a while until I put the new tune on the chip.

Probably need to mention the A/F gauge is only tied to the left side o2 sensor.

But I'm still getting 63 and 64 codes, indicating lean conditions on both sides.

Could it be the o2 sensors are plugged?

[Tyler Townsley]

Pull a plug on each side and see what they look like. Old school but effective.

[GOLDCYLON]

hmm swaping from lean to rich? It sounds like a bad o2 sensor as one side is trying to compensate for the other or maybe a bad cat on one side causing the values to bounce?

[-=Jeff=-]

no the A/F gauge is on a narrow band O2.. I am guessing the OEM one right?

Anyway, it will go back and forth.. better bet is having a wideband with gauge to be accurate

[kenthompson]

hmm swaping from lean to rich? It sounds like a bad o2 sensor as one side is trying to compensate for the other or maybe a bad cat on one side causing the values to bounce?

What's a cat? ;););)

[kenthompson]

no the A/F gauge is on a narrow band O2.. I am guessing the OEM one right?

Anyway, it will go back and forth.. better bet is having a wideband with gauge to be accurate

I agree, it got installed just as a check. Are you saying that is normal behavior?

I'm going to have to find my laptop that I used for recording on the diag connector so I can post voltages.

[-=Jeff=-]

I agree, it got installed just as a check. Are you saying that is normal behavior?

I'm going to have to find my laptop that I used for recording on the diag connector so I can post voltages.


yes typical OEM O2 will swing lean to rich..

a Wideband would confirm for sure..

[XfireZ51]

O2 voltages are supposed to "swing" through a x-over point. So it is normal to see lean rich lean. The cat would be damaged otherwise. NB voltages are meaningless at WOT.

[kenthompson]

Changed the plugs tonight, (if I could figure out how to post pictures I would). Left bank appeared to be normal, gray-brown across ground strap and down center electrode. Right bank showed brown/gray across the underside of the ground strap (spark side) and the center electrode. The rest of it was black but dry. Number 5 had broken the porcelin (sp) on the center electrode and had basically shorted out.

Also changed out the O2 sensors (cheap insurance I thought).

Car runs a lot smoother now but issued a code 64 idling in my driveway.

At least we're getting down to less and less error codes!

Guess I'll pull the fuel pumps tomorrow night.

[-=Jeff=-]

you will get it.. what is 64 again?

[kenthompson]

you will get it.. what is 64 again?

Left side lean, I believe. Or right side lean.

[XfireZ51]

Rt side. May want to check injectors.