Test pipes vs HFCs and related questions

spearfish25

Not much. We're talking less than 5hp.

You buy a brand that has a good track record. I have 6k mi on my ERZ HFCs and no CEL.

There is no need to get a tune after adding either test pipes or HFCs. The computer can adjust A/F ratios to keep things in range. The tune becomes necessary when you've done more than three bolt-ons (cbe, hfcs, intakes, headers). Doing all four can lead to lean situations and a tune is highly recommended by the tuning companies sponsoring this site.

Remember that test pipes have some negatives that may not offset the marginal hp gain over HFCs. 1) more rasp: HFCs have some, test pipes have more. 2) smell: your exhaust will wreak after adding test pipes. 3) bumper stains: the uncatalyzed exhaust can leave yellow tinges to your rear bumper that require some additional 'work' to remove when washing the car. 4) noise: test pipes will be louder overall than hfcs. 5) emissions: in states that check computer codes, both should pass as long as there is no CEL. If they use a sniffer, a HFC has a small chance of passing, test pipes don't have a prayer.

Hope that helps.

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2013 Cadillac V-Wagon, RIP Z