1988 Toyota Pickup 1988 Toyota Truck Won't Pass CA Smog

Tiny
CM1LLS
  • MEMBER
  • 1988 TOYOTA PICKUP
  • 4 CYL
  • 4WD
  • MANUAL
  • 18,900 MILES
Hello I have a 1988 Toyota pick-up, its a 4 banger with 4wd (manual). I recently took it in to get it smogged in California and it passed everything (visual and functional) except the emission test because of the NO and CO. The truck had been sitting for a while besides the occasional start up and let it sit for a little bit and used to pass no problem, but now it wont. Below are the emission results. The person who tested it said that the reason the first CO was high was probably because the NO or it wasn't hot enough. Before we got the test we ran it for a while and made sure to have barely any gas in it and then filled it. Once we got there and sat for a while and probably cooled down. I was wondering if anyone has any ideas on what is wrong and/or what I should check out. ANY HELP WOULD BE GREATLY APPRECIATED.

TEST (15mph)

RPM: 1612

%CO2: 14.1

%O2: 0.8

HC (PPM)- MAX:135 MEAS:106

CO (%)- MAX:0.87 MEAS:0.91

NO (PPM)- MAX:1058 MEAS:2410

TEST (25mph)

RPM:2537

%C02: 14.1

%O2: 0.8

HC (PPM)- MAX:115 MEAS: 42

CO (%)- MAX:1.08 MEAS:0.31

NO (PPM)- MAX:918 MEAS:1738

*MAX=Maximum Allowable Emissions MEAS=Amount measured
Sunday, November 1st, 2009 AT 6:46 PM

4 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Hi Cm1lls and TY for the donation

Your NOX oxides of nitrogen is way too high try cleaning out the egr valve

CO- the system may not be going into closed loop because of a bad coolant or oxygen sensor.
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Sunday, November 1st, 2009 AT 7:01 PM
Tiny
CM1LLS
  • MEMBER
  • 3 POSTS
Ok I will do and let you know! THANKS
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Sunday, November 1st, 2009 AT 7:03 PM
Tiny
CM1LLS
  • MEMBER
  • 3 POSTS
Do you think the egr valve has a lot to do with it? Is there anything else I should do/check! THANKS
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Sunday, November 1st, 2009 AT 9:17 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Give the EGR valve a good clean up and see what happens and follow the other 2.

If the EGR valve is not opening it will raise the combustion temperature and oxides of nitrogen will form and also will cause the engine to detonate/ping
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Monday, November 2nd, 2009 AT 12:10 AM

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