mhayes2344

iTrader: (3)

I installed pacesetter longtube headers and finally got the chance to drive the car a good bit today...only to run into problems. I have not had the car tuned yet as I was planning on taking it to a mechanic and having a new cam and supporting valvetrain installed as soon as I finished installing the headers.

So on startup everything seems fine...but once it idles for a minute or two the SES light starts flashing and it doesnt seem to idle right. Driving the car, I had the same problem...would be ok for a minute or so then the SES light would start flashing and I would have a significant loss in power...gave it more throttle and it would eventually start acting right...then the SES light just stays solid and everything seems fine.

My question is, is this just because the computer has not had the rear O2 sensors tuned out and the computer having to adjust to the lt's?

HoLLo

iTrader: (17)

Did you order race style headers or EGR/AIR fitting headers?

I just installed race-style Pacesetter coated longtubes and off-road y-pipe, removed the EGR/AIR. I used 2 new O2 sensors, and installed an EGR blockoff kit. I still am running on stock tune. I have not had any performance issues whatsoever besides me burning plugwires on the headers, which is fixed now.

chavez885

iTrader: (12)

Car shouldn't studder or flash SES lights for header installs, if you bought race style headers, you need to make sure your airpump is unplugged and EGR blocked off like the poster above me said

mhayes2344

iTrader: (3)

I have the emissions headers with EGR and AIR hooked up.

something I just thought of...instead of buying O2 wire extensions I spliced them to make them longer with the wire and connecters pacesetter provides. Would a bad connection with those cause this sort of problem?

TABBED 5.3

iTrader: (1)

i tried to splice the o2 connectors as well and immediately thru codes. ended up buying o2 extensions and problem solved

mhayes2344

iTrader: (3)

yeah..I had autozone scan the computer for codes and this is what they came up with:

P0154, P0160, P0140 -- oxygen sensors

P0100 - MAF (possibly dirty?)

P0300 - multiple random misfire. This is the one that's throwing me off. I checked the plug wires and they arent burnt or anything...however the plugs were pre-gapped at .044 I believe. Do you all think that could be causing a problem? If so what should I gap them to?

deliryumtrigger

Check and make sure you don't have any burnt wires. And being that we're in the LT1 forum...not to jinx you, but this is also can be a dying Opti...

I8ASaleen

iTrader: (9)

Could be a result of that dirty MAF, just clean it with some brake cleaner then let it dry (I used a Q tip on mine, but won't recommend anyone do that).

bobdec

I assume the wires and connectors Pacesetter provided were for the harness from the computer to the sensors. If you spliced the O2 sensors on the sensor end they are probably ruined. O2 sensors require clean outside air to function correctly the air is provided from the connector thru the wire insulation to the sensor, cutting the wire and splicing destroys the outside air source. Rear O2 sensors do not effect running, they can throw CAT malfunction codes but will not cause rough idle. What year and engine R we talking about ? Plug gap is most likely 55, but I don't think 44 would throw misfires and SES codes. When it starts running OK with SES lite could be O2 sensors eventually drop out of ready and you revert to open loop. Also when just started it runs OK, same thing it's in open loop till coolant hits 140* , O2s reach about 600*, and 200 sec timer times out. Also if splices are correct make sure they are soldered, sensor current is very low and non-soldered connections can cause flakey O2 operation.

mhayes2344

iTrader: (3)

deliryumtrigger - all the plug wires are fine...zip-tied away from the headers and whatnot...checked them all earlier to see if any are melted and they look fine. I dont think its the opti as I didnt have any problems before the header install and the opti was replaced <5k miles ago...but ya never know. I'll start with the simple and cheaper stuff first haha.

I8ASaleen - cleaning the MAF sensor is on the to-do list tonight...we'll see how that goes.


bobdec -The car is a 96 lt1. I spliced the wires between the connector and sensor...which probably messed them up (no solder either). I was planning on getting the extensions and new sensors anyway...I just need the car to act right for like 30min so I can take it to my mechanic to have the cam and everything installed. One thing that throws me off though is I spliced the o2 sensor on the driver side the same way...and no problems out of it (or at least no SES code for it).

Edit: Found the problem...one of the plastic connectors I used for the extensions came loose ...gona order some actual o2 wire extensions and new o2 sensors. Thanks for the help guys.

bobdec

Try disconnecting the O2's completely, it will throw codes but will stay in open loop. Should get you to the shop..