jdb3667 Posted April 1, 2011 Report Share Posted April 1, 2011 Hey everyone I failed emissions my HC ppm was 532 and passing is 220 and my CO% was 6.16 and passing is 1.20 but only failed on idle I passed on high idle. Its a 94 lumina 3.1 with 136,000 on it. I have new plugs, wires, and thermostat. The car runs great I just bought it so Im not sure whats old and whats been preplaced. If anyone could help with what I should do next It would be very much appreciated. Thanks. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 1, 2011 Report Share Posted April 1, 2011 high HC and high CO is indiciative of the engine running much richer than stoich. how old is the cat, and is it a "high-flow" unit? Quote Link to comment Share on other sites More sharing options...
jdb3667 Posted April 1, 2011 Author Report Share Posted April 1, 2011 Everything on the car is stock Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 2, 2011 Report Share Posted April 2, 2011 well, the cat is 17 years old and has 136,000 miles on it... GM was only required to have them functioning within normal limits for 5 years/50,000 miles, so it's a possibility it's just worn out. or you are just running rich and for some reason the ECM isn't correcting for it. Quote Link to comment Share on other sites More sharing options...
Mach 5 Posted April 2, 2011 Report Share Posted April 2, 2011 o2 sensor working properly? Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted April 2, 2011 Report Share Posted April 2, 2011 That was going to be my suggestion. If it's never been replaced, I can guarantee at that mileage it might not be setting off the light, but it's not doing much, either. Quote Link to comment Share on other sites More sharing options...
jdb3667 Posted April 2, 2011 Author Report Share Posted April 2, 2011 Howd would I know if the o2 is working properly? Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 2, 2011 Report Share Posted April 2, 2011 either an ALDL cable hooked up to a laptop, or a good scanner. Quote Link to comment Share on other sites More sharing options...
jdb3667 Posted April 5, 2011 Author Report Share Posted April 5, 2011 (edited) should I change the o2 sensor first before changing the cat or is it something that should be done together? Is the sensor behind the motor on the exhaust manifold? Is there any replacement that you guys recommend for the sensor and cat because I looked on rockauto and theres a bunch or sensors to pick from. Thanks Edited April 5, 2011 by jdb3667 Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 5, 2011 Report Share Posted April 5, 2011 IIRC, Ken determined that Denso O2 sensors are what ACDelco rebranded as their own, so the correct denso or delco sensor would be ideal, certain O2 sensors seem to have issues(i want to say Bosch?) and should be avoided. yes the O2 is behind the motor, it's going to be a pain to replace. the cat isn't going to be much fun either. Quote Link to comment Share on other sites More sharing options...
jdb3667 Posted April 5, 2011 Author Report Share Posted April 5, 2011 lol yea thats what Im kinda seeing. Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted April 5, 2011 Report Share Posted April 5, 2011 I got one of the OEM oxygen sensors for my LQ1 last year from RockAuto, I think it was around $70.00. But you'll definitely need a crowsfoot wrench to get into that spot. I had my plenum off at the time, (timing belt replacement) which made the job much easier. Not much room between the plenum and upper firewall, but it does look possible. Quote Link to comment Share on other sites More sharing options...
jdb3667 Posted April 5, 2011 Author Report Share Posted April 5, 2011 on rockauto theres one for 18.00 one for 27.00 and one for 41.00. whats the difference in them? Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 5, 2011 Report Share Posted April 5, 2011 i'd grab the $12.49 Denso! or the $15.98 Delphi or even the $18.20 ACDelco. damn, did O2 sensors get cheap lately? Quote Link to comment Share on other sites More sharing options...
Crazy K Posted April 6, 2011 Report Share Posted April 6, 2011 unheated cheaper than heated. Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted April 6, 2011 Report Share Posted April 6, 2011 Way cheaper than last year. Rockauto has been clearing some of their stock of parts for our cars. Last month, I bought a spare set of spark plug wires for my LQ1 from them. Less than $60.00 for a set of AC/Delco OEM plug wires! The set I bought a year and a half ago cost twice that much. Quote Link to comment Share on other sites More sharing options...
virtuetovice Posted April 6, 2011 Report Share Posted April 6, 2011 x2 on the oxygen sensor. Wouldn't hurt to try SeaFoam in the intake either. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.