Mike635

Smog guy says vehicle is still rich, i have no trouble codes,passed visual and mechanical.2500rpm hc O154, co 3.49,at idle hc O218, co 3.04 Any ideas, ive tested and retested using tuned port book on troubleshooting,the only thing ive noticed out of the ordinary is some times my fuel pressure seems lagging when accelerating, any ideas greatly appreciated. Thanks Mike

Grim Reaper

Try changing the O2 sensor and if that doesn't work, the catalytic convertor.

Mike635

Hi, Ive changed the O2 sensor, could the readings be that far off with a bad cat? Thanks Mike

Kyle F

You mentioned your fuel pressure is lacking at acceleration. Is it also lacking at the 2500rpm test range. Of so it could cause emissions to be a little screwy because you are not getting a clean burn. The better spray pattern you get from your injectors will equal a more complete burn due to better atomization with the air flowing into the combustion chamber. KNow I don't know why you sensore wouldn't read this as a lean condition and compensate, but I am not an expert on that, I just know alot obaout what the fuel can do in the chamber. Seems to me that you might need a new pressure regulator. Check your fuel pressure at a constan engine speed of 2500rpm and see what you get. I think you might find that is is low.

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FOR SALE!!!!!!!!!!!!!!!
86 Trans Am 355 TPI Rebuilt 700R4 with Corvette servo, modified valve body, and a B&M Torque Converter (2000 rpm stall w/ lock up), 87 350 block bored .30 with new crank. Reworked 305 heads with 3-angle valve job. Added in the rebuild was an SLP TPI cam, BBK 58mm Throttle Body,MSD 6A, Hypertech Power Coil, 1.5 Crane roller tipped rocker arms, SLP Intake Runners and Port matching in upper intake including fully ported plenum, TPIS adjustable fuel pressure regulator @ 46psi, Hooker shorty style headers w/ Thermotech heat wrapping, Custom 3” exhaust with Flowmaster muffler and chrome quad tips, Hypertech Thermomaster Computer chip, K&N open element cone filter on modified MAF per TPIS specs, MSD Wires, removal of A/C hardware and added a 1LE firewall cover installed. Also there has been a PST front suspension kit with Hotchkis strut tower brace added. Soon to have Intrax lowering springs.
http://geocities.com/SunsetStrip/Garage/9548/kyle.html

Kills:
95 Talon TSI, 96 Probe GT, 91 T/A L98, 89 RS, 86 Mustang GT, 88 Mustang LX 5.0, 92 Thunderbird V8. couple or ricers that I think were Civics or Preludes not sure what year, 95 Celica GT-S, 94 Chevy 1/4 ton 350, one of those NASCAR F150's

The Third Gen Will Never be Forgotten

james_fearn

The cat helps out a LOT. I bet if you replace it you will have no problems passing. I had to install a new cat on an 86 G20 van (305 V8) and an 87 Taurus (3.0 V6) that failed initially but then passed beautifully after a new cat.

James