Jimal Temus
01-21-2007, 04:21 PM
(WARNING: This could be a long one)
THE VEHICLE:
1987 Dodge D-100, 155k miles on a rather tired 225 slant-six. Recently replaced:
- Cylinder head
- Exhaust manifold
- Head pipe (replaced front cat with plain head pipe, original rear cat retained)
- A.I.R. pipes
- "Lean Burn" computer
- Carburetor
- Tune-up parts (cap, rotor, wires, plugs, PCV, filters, etc.)
TEST RESULTS:
HC (PPM) CO (%) NOx (PPM) RPM
Limit 160 3.50 8703
Emissions 273 1.21 896 1410
Failed on hydrocarbons, but not by much, considering the truck burns a good amount of oil. In order to get the free retest, I have to have the truck serviced by a Connecticut emissions certified test center. In order to apply for a waiver, I have SPEND (a written estimate is not acceptable) a minimum of $660 on emissions-related repairs. Having spent way too much money on the whole cylinder head fiasco, I'd rather not sink another $660 into the lump currently under the hood of a truck that currently sees weekend dump/home improvement center duty.
Apart from removing the front cat, all the emissions equipment is on the truck, and in fact with the exception of the rear cat, all the emissions equipment is new. What the truck really needs is a new shortblock. I was planning on swapping in a crate V8 at some point. This isn't going to happen in the short term. The curveball here is that the registration is due in April, and the truck must be in compliance (either via passing the test or via waiver) for the registration to be renewed.
IDEAS
With all this in mind, I've come up with the following scenarios:
1. Take the truck to a shop with a gas analyzer and hope they can get the truck in spec. I know the engine is tired, and is really what needs to be replaced. I just spent a big chunk replacing the gearbox in my Golf TDI, so I'm trying to put off any large expenses on this as long as I can. Then again, I can't say the truck isn't also running rich, and that an adjustment could get it under the limit. I also get the free retest, but is it worth spending a bunch on labor to save $20 on a retest?
2. Will a modern catalytic convertor scrub the exhaust better than what is under there now? Should I invest in putting a front cat back under there? Or, would something like an MSD box, which would work nicely with my future V8 plans, burn what's ending up in the combustion chambers?
3. Some combination of the two. Replace the cat(s) myself, then bring it somewhere to see if they can adjust on it.
There it is. Any thoughts, suggestions, anecdotes?
Thanks,
Jim
THE VEHICLE:
1987 Dodge D-100, 155k miles on a rather tired 225 slant-six. Recently replaced:
- Cylinder head
- Exhaust manifold
- Head pipe (replaced front cat with plain head pipe, original rear cat retained)
- A.I.R. pipes
- "Lean Burn" computer
- Carburetor
- Tune-up parts (cap, rotor, wires, plugs, PCV, filters, etc.)
TEST RESULTS:
HC (PPM) CO (%) NOx (PPM) RPM
Limit 160 3.50 8703
Emissions 273 1.21 896 1410
Failed on hydrocarbons, but not by much, considering the truck burns a good amount of oil. In order to get the free retest, I have to have the truck serviced by a Connecticut emissions certified test center. In order to apply for a waiver, I have SPEND (a written estimate is not acceptable) a minimum of $660 on emissions-related repairs. Having spent way too much money on the whole cylinder head fiasco, I'd rather not sink another $660 into the lump currently under the hood of a truck that currently sees weekend dump/home improvement center duty.
Apart from removing the front cat, all the emissions equipment is on the truck, and in fact with the exception of the rear cat, all the emissions equipment is new. What the truck really needs is a new shortblock. I was planning on swapping in a crate V8 at some point. This isn't going to happen in the short term. The curveball here is that the registration is due in April, and the truck must be in compliance (either via passing the test or via waiver) for the registration to be renewed.
IDEAS
With all this in mind, I've come up with the following scenarios:
1. Take the truck to a shop with a gas analyzer and hope they can get the truck in spec. I know the engine is tired, and is really what needs to be replaced. I just spent a big chunk replacing the gearbox in my Golf TDI, so I'm trying to put off any large expenses on this as long as I can. Then again, I can't say the truck isn't also running rich, and that an adjustment could get it under the limit. I also get the free retest, but is it worth spending a bunch on labor to save $20 on a retest?
2. Will a modern catalytic convertor scrub the exhaust better than what is under there now? Should I invest in putting a front cat back under there? Or, would something like an MSD box, which would work nicely with my future V8 plans, burn what's ending up in the combustion chambers?
3. Some combination of the two. Replace the cat(s) myself, then bring it somewhere to see if they can adjust on it.
There it is. Any thoughts, suggestions, anecdotes?
Thanks,
Jim