MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
06-29-2017, 10:08 PM
#1
Registered User
Thread Starter
Join Date: May 2001
Posts: 234
MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
Exhaust: Hooker Long Tube headers + 3" y pipe with MagnaFlow 59959 converters + Hooker Aero chamber cat-back.
Fitted a couple MagnaFlow 59959 catalytic converters on a y-pipe today and fired it up to find that the passenger side cat was glowing red after the engine was running for a few minutes. Prior to being red hot exhaust out the the cat-back seemed normal. Once the passenger cat turned red, there appeared to be more exhaust/smoke coming out. Once I saw the glowing red I turned the car off promptly after taking a photo.
Is this normal? My LT1 is not running rich to my knowledge...my previous not catted y-pipe did not glow red hot.
Driver's side was heating up and was likely to going to turn red also. Being that the driver's side is back further I am assuming it was taking longer to warm up.
Fitted a couple MagnaFlow 59959 catalytic converters on a y-pipe today and fired it up to find that the passenger side cat was glowing red after the engine was running for a few minutes. Prior to being red hot exhaust out the the cat-back seemed normal. Once the passenger cat turned red, there appeared to be more exhaust/smoke coming out. Once I saw the glowing red I turned the car off promptly after taking a photo.
Is this normal? My LT1 is not running rich to my knowledge...my previous not catted y-pipe did not glow red hot.
Driver's side was heating up and was likely to going to turn red also. Being that the driver's side is back further I am assuming it was taking longer to warm up.
06-29-2017, 10:24 PM
#2
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,648
Re: MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
Could be excessive misfires. Unburned fuel and air exit the misfiring cylinder, and the catalyst promotes combustion, which takes place on the substrate. Will melt the substrate and destroy the cat. One possibility.
No info/signature provided on the year of the car. Is it a 96, as suggested by your screen name? If so, any codes for misfires?
No info/signature provided on the year of the car. Is it a 96, as suggested by your screen name? If so, any codes for misfires?
06-30-2017, 08:13 AM
#3
Registered User
Thread Starter
Join Date: May 2001
Posts: 234
Re: MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
1996 Z28. Manual transmission.
(I have OBD2-scanner software/cable for pc and good old LT1 Edit)
Engine
58mm Throttle Body
Port & Polished the MAF sensor
throttle body by-pass
!CAGS
SLP Cold Air Induction
Comp Cams 306 cam (230 / 244, .510 / .549 112 LSA)
LT4 Timing Chain
Port and Polished Heads
Mr. Gasket Head Gaskets (.026 thick)
Port and Polished Intake (and 58mm Throttle Body ready)
Comp Cams 1.6 Roller Rockers
Comp Cams Hardened Push Rods
Comp Cams "R" Series Hydraulic Roller Lifters
Crane Dual Valve Springs
Comp Cams Guide Plates
Taylor Pro Spiral 8mm wires
1LE Elbow
LT4 Knock Module
Fuel Pressure Regulator (T.P.I.S. Top Hat Kit)
CSI Electric Water Pump
MSD 6AL ignition box
Exhaust
Hooker Long Tubes with JetHot 2000 coating
Pacesetter Y-Pipe (Modified to mate up to Hooker LTs. Summer 2017)
MagnaFlow 59959 catalytic converters (Summer 2017)
Hooker Aero Chamber Cat-back
Suspension
Eibach Proline Springs
T.P.I.S. Strut Tower Brace
Boxed PanHard Rod
Spohn Adjustable Torque Arm (Spring 2008)
Y Pipe looking top down (before joints were welded).
Y Pipe installed from rear.
https://www.camaroz28.com/forums/att...1&d=1498828187
(I have OBD2-scanner software/cable for pc and good old LT1 Edit)
Engine
58mm Throttle Body
Port & Polished the MAF sensor
throttle body by-pass
!CAGS
SLP Cold Air Induction
Comp Cams 306 cam (230 / 244, .510 / .549 112 LSA)
LT4 Timing Chain
Port and Polished Heads
Mr. Gasket Head Gaskets (.026 thick)
Port and Polished Intake (and 58mm Throttle Body ready)
Comp Cams 1.6 Roller Rockers
Comp Cams Hardened Push Rods
Comp Cams "R" Series Hydraulic Roller Lifters
Crane Dual Valve Springs
Comp Cams Guide Plates
Taylor Pro Spiral 8mm wires
1LE Elbow
LT4 Knock Module
Fuel Pressure Regulator (T.P.I.S. Top Hat Kit)
CSI Electric Water Pump
MSD 6AL ignition box
Exhaust
Hooker Long Tubes with JetHot 2000 coating
Pacesetter Y-Pipe (Modified to mate up to Hooker LTs. Summer 2017)
MagnaFlow 59959 catalytic converters (Summer 2017)
Hooker Aero Chamber Cat-back
Suspension
Eibach Proline Springs
T.P.I.S. Strut Tower Brace
Boxed PanHard Rod
Spohn Adjustable Torque Arm (Spring 2008)
Y Pipe looking top down (before joints were welded).
Y Pipe installed from rear.
https://www.camaroz28.com/forums/att...1&d=1498828187
Last edited by tryme96Z; 07-01-2017 at 02:05 PM. Reason: Removed incorrect OBD2 scan information
06-30-2017, 08:41 AM
#4
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,648
Re: MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
Are you saying BOTH O2's are static in the 440's? That could mean the O2's are not warming up, or they are faulty. Does the scanner indicate both O2's are "ready"?
Should be going into closed loop at 206-seconds. But if it's been running for 5 minutes and coolant is only 131°F, may not be warm enough to allow it to go into closed loop. O2's have to be hot and coolant has to be above a variable threshold to enter closed loop.
With that cam you have a bit if overlap, and at idle, the blow-thru of fresh A/F mix could be burning on the cat. Also, depending on the tune, the PCM could still be operating in cold start enrichment, causing an even larger amount of fuel to burn on the cat. The purpose of the catalytic substrate is (in part) to promote oxidation (= combustion). As a result the combustion in the presence of high O2 content is intense. Could also be the valve adjustment is too tight on side that is glowing.
With that cam I would assume misfire detection is disabled in the tune, because just the chop would be misinterpreted as misfires.
Where are you measuring the 14.3:1 A/F ratio? Wideband? Both sides, one side or singlcombined?
Figure out why it's not going into closed loop.
Should be going into closed loop at 206-seconds. But if it's been running for 5 minutes and coolant is only 131°F, may not be warm enough to allow it to go into closed loop. O2's have to be hot and coolant has to be above a variable threshold to enter closed loop.
With that cam you have a bit if overlap, and at idle, the blow-thru of fresh A/F mix could be burning on the cat. Also, depending on the tune, the PCM could still be operating in cold start enrichment, causing an even larger amount of fuel to burn on the cat. The purpose of the catalytic substrate is (in part) to promote oxidation (= combustion). As a result the combustion in the presence of high O2 content is intense. Could also be the valve adjustment is too tight on side that is glowing.
With that cam I would assume misfire detection is disabled in the tune, because just the chop would be misinterpreted as misfires.
Where are you measuring the 14.3:1 A/F ratio? Wideband? Both sides, one side or singlcombined?
Figure out why it's not going into closed loop.
06-30-2017, 09:14 AM
#5
Registered User
Thread Starter
Join Date: May 2001
Posts: 234
Re: MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
o2 readings are fluctuating. Standard Bosch o2s. No wideband (can I connect a wideband into the stock harness/ecm? I assumed separate reading hardware is needed).
Programming was done by PCMforLess. Sent them mod list and they sent a file I uploaded via LT1Edit back in 2002. At the time I had no cats…not sure if that would have impacted their program.
A/F is just what obdII is reporting from the stock narrow band o2s. A/F is listed as a single data point.
I'll fire it up again this evening and see if I can get into closed loop before cat gets too hot and get more details. The 5 minutes of run time is just idling, no revving or driving.
Thank you Fred!
Programming was done by PCMforLess. Sent them mod list and they sent a file I uploaded via LT1Edit back in 2002. At the time I had no cats…not sure if that would have impacted their program.
A/F is just what obdII is reporting from the stock narrow band o2s. A/F is listed as a single data point.
I'll fire it up again this evening and see if I can get into closed loop before cat gets too hot and get more details. The 5 minutes of run time is just idling, no revving or driving.
Thank you Fred!
06-30-2017, 05:10 PM
#6
Registered User
Thread Starter
Join Date: May 2001
Posts: 234
Re: MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
Going into Closed loop at about 90 seconds of run time. AF is reading as 14.7. Still no trouble code. o2s reading 300-900 fluctuating independently of each other. Does not appear to be any current misfires being detected by OBD2.
This time (second start on cats), the driver's side (the one that did not turn red last time) turned red hot before the passenger's side (which turned red first on the last start).
After 8 minutes of idling neither cat was red. So I reved to 3k and held that for about 30 seconds. A minute later I observed the red driver's side cat and a minute later the passenger side also started turning red.
For the AF ratio, OBD-2 Vehicle Explorer Scan Tool Browser software serves up a single data point from the stock narrow band o2s.
This time (second start on cats), the driver's side (the one that did not turn red last time) turned red hot before the passenger's side (which turned red first on the last start).
After 8 minutes of idling neither cat was red. So I reved to 3k and held that for about 30 seconds. A minute later I observed the red driver's side cat and a minute later the passenger side also started turning red.
For the AF ratio, OBD-2 Vehicle Explorer Scan Tool Browser software serves up a single data point from the stock narrow band o2s.
Last edited by tryme96Z; 06-30-2017 at 05:14 PM.
06-30-2017, 09:58 PM
#7
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,648
Re: MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
Where are you reading the A/F ratio? The PCM tells you the "target" A/F ratio it is trying to achieve. Does not tell you the actual A/F ratio. That's why I asked if you had a wideband sensor.
How can your new info be so much different than your first set of data? 90 seconds to closed loop vs 5 minutes still in open loop, O2’s moving vs earlier 442.7 (note, you described that as the reading of the O2's... plural - that's why I asked if it was BOTH sides). Hard to reconcile the huge differences in the twp posts.
Really can't offer any additional input based on the new data. Too confusing.
How can your new info be so much different than your first set of data? 90 seconds to closed loop vs 5 minutes still in open loop, O2’s moving vs earlier 442.7 (note, you described that as the reading of the O2's... plural - that's why I asked if it was BOTH sides). Hard to reconcile the huge differences in the twp posts.
Really can't offer any additional input based on the new data. Too confusing.
06-30-2017, 11:15 PM
#8
Registered User
Thread Starter
Join Date: May 2001
Posts: 234
Re: MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
Post #3 (previous OBDII data) was wrong due to opening the wrong file for viewing when posting here. Post #6 data is correct. Sorry for the mixup.
Video of idling and cats glowing. https://sendvid.com/k1j3e7xu This video was shot during the data gathering for Post #6.
Video of idling and cats glowing. https://sendvid.com/k1j3e7xu This video was shot during the data gathering for Post #6.
Last edited by tryme96Z; 07-01-2017 at 03:27 PM. Reason: Added video.
07-27-2017, 08:00 AM
#9
Registered User
Thread Starter
Join Date: May 2001
Posts: 234
Re: MagnaFlow 59959 cat glowing red (photo) - LT1 with LT headers
Adjusting the valve lashed seems to have helped bring the temperature down.
After further analysis, there is a lean condition on bank 2 causing LTFTs to be 25% at idle. This is most likely related to a leak on bank 2 since the high LTFTs go down as soon as the rpms go up.
After further analysis, there is a lean condition on bank 2 causing LTFTs to be 25% at idle. This is most likely related to a leak on bank 2 since the high LTFTs go down as soon as the rpms go up.