EGR 89GT bypass [tru cold air]
-
- Registered User
- Posts: 288
- Joined: Tue Jan 15, 2002 10:00 am
- Location: Maryville, TN
EGR 89GT bypass [tru cold air]
I plugged the vacuum line going to my vacuum style EGR valve in attempt to raise combustion temperatures [by cold air intake] for greater efficiency.
MY OXY SENSOR code 13 is cycling on/off while driving at 50mph every ... seems like a fixed time interval... stays on for some seconds [prob not over a min, but could be close to] and stays off for a while... returns... repeats
I'm running NON alcoholic 87 octane [texaco sells this for those of you non turbo high compression people].
my question is, since my o2 sensor is older... [mid life, 8k mi on it] is it going out?
should my ecu need modifying/replacing?
is the o2 signal off the map now due to egr bypass?
I wonder if I can put a bosch sensor in there... but if its off the computer map, then it won't make a difference, which is why I post here...
Where is the info on bypassing this?
Andy <--- surely not the first to do this
MY OXY SENSOR code 13 is cycling on/off while driving at 50mph every ... seems like a fixed time interval... stays on for some seconds [prob not over a min, but could be close to] and stays off for a while... returns... repeats
I'm running NON alcoholic 87 octane [texaco sells this for those of you non turbo high compression people].
my question is, since my o2 sensor is older... [mid life, 8k mi on it] is it going out?
should my ecu need modifying/replacing?
is the o2 signal off the map now due to egr bypass?
I wonder if I can put a bosch sensor in there... but if its off the computer map, then it won't make a difference, which is why I post here...
Where is the info on bypassing this?
Andy <--- surely not the first to do this
- IsaacHayes
- Registered User
- Posts: 975
- Joined: Fri Oct 07, 2005 8:32 pm
- Location: Missouri
Re: EGR 89GT bypass [tru cold air]
Blocking the EGR shouldn't affect the O2 at all.
Don't get Bosch sensors they aren't good. Go with Denso or AC Delco. www.sparkplugs.com has Denso for cheap, is where I got mine.
Check the wires going to the O2, maybe it's as simple as a broken wire or something.
Don't get Bosch sensors they aren't good. Go with Denso or AC Delco. www.sparkplugs.com has Denso for cheap, is where I got mine.
Check the wires going to the O2, maybe it's as simple as a broken wire or something.
Re: EGR 89GT bypass [tru cold air]
yellow3800 wrote:I plugged the vacuum line going to my vacuum style EGR valve in attempt to raise combustion temperatures [by cold air intake] for greater efficiency.
MY OXY SENSOR code 13 is cycling on/off while driving at 50mph every ... seems like a fixed time interval... stays on for some seconds [prob not over a min, but could be close to] and stays off for a while... returns... repeats
I'm running NON alcoholic 87 octane [texaco sells this for those of you non turbo high compression people].
my question is, since my o2 sensor is older... [mid life, 8k mi on it] is it going out?
should my ecu need modifying/replacing?
is the o2 signal off the map now due to egr bypass?
I wonder if I can put a bosch sensor in there... but if its off the computer map, then it won't make a difference, which is why I post here...
Where is the info on bypassing this?
Andy <--- surely not the first to do this
The o2 sensor has nothing to do with the MAP sensor. The o2 simply reads the amount of un-burned fuel in the exhaust to adjust A/F ratio accordingly. Now, I could see blocking off the EGR causng a MAP sensor light due to the fact that you don't have exhaust gases traveling into the intake anymore.
SIDE NOTE --- if you are trying to make a "true cold air intake" did you already bypass the coolant lines running into the T/B? Otherwise blocking off the EGR did no real gain if you still have coolant lines hooked up to your T/B.
- Ryan -
1987 Jeep Wrangler 4x4
1995 Chevy S10 Ext. Cab 4x4
1987 Jeep Wrangler 4x4
1995 Chevy S10 Ext. Cab 4x4
- IsaacHayes
- Registered User
- Posts: 975
- Joined: Fri Oct 07, 2005 8:32 pm
- Location: Missouri
Re: EGR 89GT bypass [tru cold air]
I think he means by "off the map" like "off the charts" "way off reading" etc...
And since the older ones were vacuum only I don't think you will even get a check engine light. Now something like a 3100 will know if it's not flowing even due to a blocked passage AFTER the EGR!! It does read the MAP and expect a change when it opens the EGR.
And since the older ones were vacuum only I don't think you will even get a check engine light. Now something like a 3100 will know if it's not flowing even due to a blocked passage AFTER the EGR!! It does read the MAP and expect a change when it opens the EGR.
Re: EGR 89GT bypass [tru cold air]
Yea, now that I read that again I see that. When I read it the first time I thought he meant his MAP sensor. Not "off the map" LOL Oops....
- Ryan -
1987 Jeep Wrangler 4x4
1995 Chevy S10 Ext. Cab 4x4
1987 Jeep Wrangler 4x4
1995 Chevy S10 Ext. Cab 4x4
- Money pit Beretta
- Registered User
- Posts: 6411
- Joined: Thu Jul 26, 2007 11:36 am
- Location: Kansas
Re: EGR 89GT bypass [tru cold air]
Not to be a jerk, but the older cars didn't have coolant lines to the TB.
keep'em flying!
-
- Registered User
- Posts: 21
- Joined: Mon Feb 09, 2004 4:58 am
- Location: Middletown, New Jersey
Re: EGR 89GT bypass [tru cold air]
Yes they do, and simply plugging off the EGR's vacuum will not create a colder intake charge. The exhaust gas still heats up the EGR tube to the exhaust manifold and in turn heats the aluminum EGR valve base, which will still heat the intake manifold.
I'm no tree hugger, but it's put there for a reason, you should be using it.
I'm no tree hugger, but it's put there for a reason, you should be using it.
Rob
'91 Beretta GT 3400 5 Speed
3400's Best 1/4 Mile
R/t .506
60' 2.195
330' 6.138
1/8 9.390 @ 76.48
1000' 12.183
1/4 14.553 @ 94.01
'91 Beretta GT 3400 5 Speed
3400's Best 1/4 Mile
R/t .506
60' 2.195
330' 6.138
1/8 9.390 @ 76.48
1000' 12.183
1/4 14.553 @ 94.01
Re: EGR 89GT bypass [tru cold air]
Just to clarify, YES, older models have the coolant lines on the throttle body. I removed it on my '89 and have yet to do it on my '90. And as far as I know... removing the EGR will do nothing for performance.
1989 GTU - The Nice Car
1989 GTU Mock - The Neglected Car
1989 Base Model - The Rally Car
1989 GTU Mock - The Neglected Car
1989 Base Model - The Rally Car
- IsaacHayes
- Registered User
- Posts: 975
- Joined: Fri Oct 07, 2005 8:32 pm
- Location: Missouri
-
- Registered User
- Posts: 21
- Joined: Mon Feb 09, 2004 4:58 am
- Location: Middletown, New Jersey
Re: EGR 89GT bypass [tru cold air]
I'd also like to point out, blocking off the EGR as per the service manual ...
Aka blocking it off, does exactly the opposite of what you wanted to achieve.Beretta Service Manual wrote:Too little or no EGR flow allows combustion temperatures to get too high. This could cause : Spark knock (detonation). , Engine overheating. , and Emission Test Failure.
- Money pit Beretta
- Registered User
- Posts: 6411
- Joined: Thu Jul 26, 2007 11:36 am
- Location: Kansas
Re: EGR 89GT bypass [tru cold air]
I could swear that my old 90GT didn't have the lines.
keep'em flying!
- 3X00-Modified
- Administrator
- Posts: 10912
- Joined: Thu Jul 05, 2007 9:18 am
- Location: Brooklyn CT
Re: EGR 89GT bypass [tru cold air]
94-95 lacked them 96 they came back.IsaacHayes wrote:1994 3100's don't have it though.
- IsaacHayes
- Registered User
- Posts: 975
- Joined: Fri Oct 07, 2005 8:32 pm
- Location: Missouri
Re: EGR 89GT bypass [tru cold air]
It operates at partial throttle at like cruise mainly highway speeds. And when slowing down to around 40 I think it opens then too.