Hi , I'v posted about this many times . Iv had the whole egr system checked , and changed allmost everything that goes with it. the only thing is that my exhuast is to free flowing , because my car uses a negative pressure egr vale , so it needs back presure. and I have the dual cats and one of them is half gone , and with the flowmaster muffler i was wondering if that could really be the problem. I have new cats and slp exhuast to go on it . so hopefully that might solve the problem . also can the negative presure egr system can be converted to a positive egr system? I was told it could be , Im just trying to find out on my own.
Thanks again

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Pino
91'Formula
LB9 305 TPI 5-speed
WS6 17" wheels
Eibach Pro-Kit Springs
Hotchkiss STB
SLP exhuast
SLP Cold Air Induction
CatCo Hi Flo Cats
http://www.geocities.com/MotorCity/Garage/5654/mur91.jpg
and the for ever returning CODE 32

 

A friend of mine has a 91 Formula Trans Am 1LE with pretty much the same exact set up you have. It's a 5 speed with SLP 1 5/8" Headers, dual cats, and SLP Cat Back Exhaust. He also has a recurring code for the EGR. I'm pretty sure that his code began after he did the exhaust headers. I think it's pretty common with the Speed Density systems after exhaust mods. Definitely replace the catalytic converters if they are going bad. One way to check for sure if they have gone bad is to bang on them with your fist. If they rattle than for sure you will need new ones. Try taking care of that first and see if you still have the recurring code.

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1988 GTA 5.7L TPI Auto
355 ci. block, SLP Cold Air Intake w/ K&N, fully modified MAF Sensor, TPIS 52mm Throttle Body w/Air Foil, Fully Ported and Polished Plenum, Nikel-plated Ported SLP Siamesed Runners, Ported TPIS Big Mouth Intake Manifold, stock heads w/ 1.52 Comp Cams Self-aligning Roller Rockers, TPIS ZZ-9 Roller Camshaft, TPIS Valve Springs, Cloyes True Double Roller Timing Chain, TPIS Adjustable Fuel Pressure Regulator, Ford Motorsports SVO 30 lb/hr Fuel Injectors, MSD 6AL, Taylor 10mm Wires, Bosch Platinum +4 Spark Plugs, MSD Blaster Coil, MSD Shift Light, March Underdrive Pulleys, 6 3/4" Vibratech Streetdamper, TPIS Level 4 PROM, 160 T-stat, Low Temp. Fan Switch, Stock Distributor w/ Bronze Gear, SLP 1 3/4" Headers, Random Technologies High Flow Cat., Adjustable Borla Cat Back Exhaust, Flow Tech Pre-Cat 3" Exhaust Cut Off, ZR1 Heated O2 Sensor, Level 10 PTS-3 700R4 Trans, B&M Holeshot 2400 Stall Converter, B&M Trans Cooler, TCI Aluminum Finned Trans Pan, Torque Converter Lock Up Switch, 3" Balanced Aluminum Driveshaft, 3.73 Richmond Gears, Auburn Pro-Series Differential, Aluminum Differential Cover w/ Main Cap Preloads, BF Goodrich Drag Radials 255/50 R16, Hotchkis Lower Control Arms, Hotchkis Panhard Rod, Hotchkis Tie Rod Adjuster Sleeves, Bilstein Heavy Duty Shocks and Struts, 1LE Springs, Energy Suspension Polyeurethane Bushings, Global West Tubular Subframe Connectors, Global West Steering Box Brace, HP Motorsports 3 Point Strut Tower Brace

"Why ride a stang when birds can fly?"

http://www.geocities.com/thegta

 

Yeah , i had the cat rattle apart tewo years ago i took the muffler off a drove around a few days and let the pieces shoot out ,, but im defanitly going to try and see what happeneds. I hope it takes car , of it , I know flowmaster as they get older the breakin more and become more free flowing.

 

Damn code 32

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91 Formula
305 TPI 5speed
1LE/G92/WS6

Paxton SN92 polished kit, SLP airfoil, ported/polished plenum, March pulleys, Crane AFPR(43psi),Crane Gold 1.6rrs,MSD coil,MSD6AL (5200rpm limit),Holley 9mm wires,Ac delco R43ts plugs,stock chip,Ford SVO 24# injectors,Bosch O2sensor,SLP 1 5/8" headers,SLP catback,shortened shifter,3:73s w/Auburn posi,170* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.

 

I don't have any problems with my EGR with my headers and lower restriction cats/exhaust.

Are you sure you have the right EGR for your car? Is your Air Diverter functioning and connected to your cats?

 

everything is working properly , you might have a positive egr valve , where as I have a negative presure vale which works off the back preasure of the exhuast

 

I've always had the same problem as you guys, ever since I put on my headers. I eventually learned to ignore it, but when I had to take off my intake manifold I found the culprit: one of the egr ports in the manifold was totally blocked up with black carbon crap. I cleaned it out, and now after about a week (which includes highway driving, which is when it always came on for me), I still haven't gotten the code.

Brandon

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White '92 Firebird w/ 305 TBI. Open element w/ non drop base, increased fuel pressure, TBI spacer, Hedman Hedders & y-pipe, no cat, cat-back exhaust

 

Pino,

I would suspect you would have more of a problem with a positive backpressure EGR valve. A positive pressure valve has a pilot valve that is normally open, preventing the EGR main valve from opening. It requires exhaust gas pressure (restriction) to close the pliot valve and regulate EGR main valve flow.

A negative backpressure valve has the pilot valve normally closed to regulate EGR main valve flow. This pilot valve is opened when exhaust pressure is high, as on heavy acceleration and higher exhaust pressure.

If you exhaust pressure is abnormally low due to an open exhaust system, the negative valve would actually be a better choice if the valve is not operating at all.

Before you decide, you need to understand that the ECM will set a DTC for the EGR for multiple reasons. If the EGR doesn't flow when expected (not opening) the code will be set. If the EGR does flow when the ECM does NOT expect it, the code will set. Both of these are determined by the reading of the EGR diagnostic temperature sensor at the base of the EGR valve, and the programmed/calculated expectaions of the ECM depending on engine speed, load, temperature, and throttle position.

If the EGR vacuum solenoid does not present an electrical load to the output terminal of the ECM, the code will set. This is monitored by a pull-up resistor internal to the ECM output circuit (which actually grounds the EGR solenoid to complete the circuit).

If you're certain that your engine originally had the negative backpressure valve, double check the vacuum hose connections at the EGR solenoid to make sure they were not reversed. You should also verify that there is adequate vacuum to the solenoid from the hose nipple on the underside of the throttle body. This vacuum line is shared with the EVAP canister purge control, and if there is a leak in either system, vacuum may not be available to operate the EGR valve when expected.

You should also make sure there is a 12VDC source at the EGR solenoid when the ignition is on, and that the connection from the solenoid to the ECM has continuity.

If you still have problems, check back with test results.

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

 

WEll Im positive i have a negative egr valve , it also doesnt have the tempature sesor at the base of the egr valve, Iv had or i have checked everything , i'v been going by the pontiac repair manual for 91 and a 92 and from what i have read it states that a negative preasur valve will bleed off if there isnt enough back preassure to hold the spring , opposed to when vacume is applied and that is when its supposed to bleep off. unlessim reading it wrong , if i had the book here at work i would quote it. ill try and bring it in tomarrow

 

Well this weekend i took the flowmaster off , and i went to the parts stor and bought a 18 dollar mufflr and slapped it up , just to see if it is my exhuast thast causing my code 32 , I think with the fact that one of my cats is half gone that its just enough to set the code off but not all the time , so have had it come on yet , and i did a lot of high way driving after i put the muffler on. so well see how it goes .. CAR IS WAY QUIET NOW

 

Vader, correct except for one thing, that Pino pointed out. Speed Density cars dont have a diagnostic temp sensor on the EGR valve. They use some other method to determine if the EGR is working or not. I believe they use the MAP sensor. When the EGR valve opens, the MAP sensor will detect a change in vacuum. If it doesnt, it'll set the code.

Also, like Tab said, blocked EGR passages is a common cause of this code. You have dirty exhaust gasses flowing thru those passages. Carbon and stuff will stick to the hot passage walls, just like gunk sticks to the walls of your ateries, eventually causing a heart attack.


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West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

day three and no code 32 ,, i even theft it stored to see if it trips it again. and i i'v done allmost all highway driving

 

well two weeks later and it came back this morning,, well time to change the cats

 

Id suggest checking into exactly what that code means. I am throwing that code too and am trying to deal with it. my case is definitly a little different than yours though, i have no mor egr vave, due to the hsr. but i talked to some of my tech friends, and they told me you throw the code when your o2 sensor dosent read the proper drop or jump, dont remember which, in exhause combustion ratio, so you may want to try changing the o2 sensor as well, could be totally wrong but it couldnt hurt to ask around.